drm_irq.c 52.7 KB
Newer Older
D
Daniel Vetter 已提交
1 2
/*
 * drm_irq.c IRQ and vblank support
L
Linus Torvalds 已提交
3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34
 *
 * \author Rickard E. (Rik) Faith <faith@valinux.com>
 * \author Gareth Hughes <gareth@valinux.com>
 */

/*
 * Created: Fri Mar 19 14:30:16 1999 by faith@valinux.com
 *
 * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */

35
#include <drm/drmP.h>
J
Jesse Barnes 已提交
36
#include "drm_trace.h"
37
#include "drm_internal.h"
L
Linus Torvalds 已提交
38 39

#include <linux/interrupt.h>	/* For task queue support */
40
#include <linux/slab.h>
L
Linus Torvalds 已提交
41

42
#include <linux/vgaarb.h>
43
#include <linux/export.h>
44 45

/* Access macro for slots in vblank timestamp ringbuffer. */
46 47
#define vblanktimestamp(dev, crtc, count) \
	((dev)->vblank[crtc].time[(count) % DRM_VBLANKTIME_RBSIZE])
48 49 50 51 52 53 54 55 56 57 58

/* Retry timestamp calculation up to 3 times to satisfy
 * drm_timestamp_precision before giving up.
 */
#define DRM_TIMESTAMP_MAXRETRIES 3

/* Threshold in nanoseconds for detection of redundant
 * vblank irq in drm_handle_vblank(). 1 msec should be ok.
 */
#define DRM_REDUNDANT_VBLIRQ_THRESH_NS 1000000

59 60 61 62
static bool
drm_get_last_vbltimestamp(struct drm_device *dev, int crtc,
			  struct timeval *tvblank, unsigned flags);

63 64 65 66 67 68 69 70 71 72 73 74 75 76
static unsigned int drm_timestamp_precision = 20;  /* Default to 20 usecs. */

/*
 * Default to use monotonic timestamps for wait-for-vblank and page-flip
 * complete events.
 */
unsigned int drm_timestamp_monotonic = 1;

static int drm_vblank_offdelay = 5000;    /* Default to 5000 msecs. */

module_param_named(vblankoffdelay, drm_vblank_offdelay, int, 0600);
module_param_named(timestamp_precision_usec, drm_timestamp_precision, int, 0600);
module_param_named(timestamp_monotonic, drm_timestamp_monotonic, int, 0600);

77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106
static void store_vblank(struct drm_device *dev, int crtc,
			 unsigned vblank_count_inc,
			 struct timeval *t_vblank)
{
	struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
	u32 tslot;

	assert_spin_locked(&dev->vblank_time_lock);

	if (t_vblank) {
		/* All writers hold the spinlock, but readers are serialized by
		 * the latching of vblank->count below.
		 */
		tslot = vblank->count + vblank_count_inc;
		vblanktimestamp(dev, crtc, tslot) = *t_vblank;
	}

	/*
	 * vblank timestamp updates are protected on the write side with
	 * vblank_time_lock, but on the read side done locklessly using a
	 * sequence-lock on the vblank counter. Ensure correct ordering using
	 * memory barrriers. We need the barrier both before and also after the
	 * counter update to synchronize with the next timestamp write.
	 * The read-side barriers for this are in drm_vblank_count_and_time.
	 */
	smp_wmb();
	vblank->count += vblank_count_inc;
	smp_wmb();
}

107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124
/**
 * drm_update_vblank_count - update the master vblank counter
 * @dev: DRM device
 * @crtc: counter to update
 *
 * Call back into the driver to update the appropriate vblank counter
 * (specified by @crtc).  Deal with wraparound, if it occurred, and
 * update the last read value so we can deal with wraparound on the next
 * call if necessary.
 *
 * Only necessary when going from off->on, to account for frames we
 * didn't get an interrupt for.
 *
 * Note: caller must hold dev->vbl_lock since this reads & writes
 * device vblank fields.
 */
static void drm_update_vblank_count(struct drm_device *dev, int crtc)
{
125
	struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
126
	u32 cur_vblank, diff;
127
	bool rc;
128 129 130 131 132
	struct timeval t_vblank;

	/*
	 * Interrupts were disabled prior to this call, so deal with counter
	 * wrap if needed.
133
	 * NOTE!  It's possible we lost a full dev->max_vblank_count + 1 events
134 135 136 137 138 139 140 141 142 143 144 145 146 147
	 * here if the register is small or we had vblank interrupts off for
	 * a long time.
	 *
	 * We repeat the hardware vblank counter & timestamp query until
	 * we get consistent results. This to prevent races between gpu
	 * updating its hardware counter while we are retrieving the
	 * corresponding vblank timestamp.
	 */
	do {
		cur_vblank = dev->driver->get_vblank_counter(dev, crtc);
		rc = drm_get_last_vbltimestamp(dev, crtc, &t_vblank, 0);
	} while (cur_vblank != dev->driver->get_vblank_counter(dev, crtc));

	/* Deal with counter wrap */
148 149
	diff = cur_vblank - vblank->last;
	if (cur_vblank < vblank->last) {
150
		diff += dev->max_vblank_count + 1;
151 152

		DRM_DEBUG("last_vblank[%d]=0x%x, cur_vblank=0x%x => diff=0x%x\n",
153
			  crtc, vblank->last, cur_vblank, diff);
154 155
	}

156
	DRM_DEBUG("updating vblank count on crtc %d, missed %d\n",
157 158
		  crtc, diff);

159 160 161
	if (diff == 0)
		return;

162 163
	/*
	 * Only reinitialize corresponding vblank timestamp if high-precision query
164 165
	 * available and didn't fail. Otherwise reinitialize delayed at next vblank
	 * interrupt and assign 0 for now, to mark the vblanktimestamp as invalid.
166
	 */
167 168 169 170
	if (!rc)
		t_vblank = (struct timeval) {0, 0};

	store_vblank(dev, crtc, diff, &t_vblank);
171 172
}

173 174 175 176 177 178 179 180
/*
 * Disable vblank irq's on crtc, make sure that last vblank count
 * of hardware and corresponding consistent software vblank counter
 * are preserved, even if there are any spurious vblank irq's after
 * disable.
 */
static void vblank_disable_and_save(struct drm_device *dev, int crtc)
{
181
	struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
182 183 184
	unsigned long irqflags;
	u32 vblcount;
	s64 diff_ns;
185
	bool vblrc;
186
	struct timeval tvblank;
187
	int count = DRM_TIMESTAMP_MAXRETRIES;
188 189 190 191 192 193 194

	/* Prevent vblank irq processing while disabling vblank irqs,
	 * so no updates of timestamps or count can happen after we've
	 * disabled. Needed to prevent races in case of delayed irq's.
	 */
	spin_lock_irqsave(&dev->vblank_time_lock, irqflags);

195
	/*
M
Martin Peres 已提交
196
	 * If the vblank interrupt was already disabled update the count
197 198 199 200
	 * and timestamp to maintain the appearance that the counter
	 * has been ticking all along until this time. This makes the
	 * count account for the entire time between drm_vblank_on() and
	 * drm_vblank_off().
201 202 203 204 205 206
	 *
	 * But only do this if precise vblank timestamps are available.
	 * Otherwise we might read a totally bogus timestamp since drivers
	 * lacking precise timestamp support rely upon sampling the system clock
	 * at vblank interrupt time. Which obviously won't work out well if the
	 * vblank interrupt is disabled.
207
	 */
208
	if (!vblank->enabled &&
209
	    drm_get_last_vbltimestamp(dev, crtc, &tvblank, 0)) {
210 211 212 213 214
		drm_update_vblank_count(dev, crtc);
		spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
		return;
	}

215 216 217 218 219 220 221 222 223
	/*
	 * Only disable vblank interrupts if they're enabled. This avoids
	 * calling the ->disable_vblank() operation in atomic context with the
	 * hardware potentially runtime suspended.
	 */
	if (vblank->enabled) {
		dev->driver->disable_vblank(dev, crtc);
		vblank->enabled = false;
	}
224 225 226 227 228 229 230 231 232 233 234 235 236 237

	/* No further vblank irq's will be processed after
	 * this point. Get current hardware vblank count and
	 * vblank timestamp, repeat until they are consistent.
	 *
	 * FIXME: There is still a race condition here and in
	 * drm_update_vblank_count() which can cause off-by-one
	 * reinitialization of software vblank counter. If gpu
	 * vblank counter doesn't increment exactly at the leading
	 * edge of a vblank interval, then we can lose 1 count if
	 * we happen to execute between start of vblank and the
	 * delayed gpu counter increment.
	 */
	do {
238
		vblank->last = dev->driver->get_vblank_counter(dev, crtc);
239
		vblrc = drm_get_last_vbltimestamp(dev, crtc, &tvblank, 0);
240
	} while (vblank->last != dev->driver->get_vblank_counter(dev, crtc) && (--count) && vblrc);
241 242 243

	if (!count)
		vblrc = 0;
244 245 246 247

	/* Compute time difference to stored timestamp of last vblank
	 * as updated by last invocation of drm_handle_vblank() in vblank irq.
	 */
248
	vblcount = vblank->count;
249 250 251 252 253 254 255 256 257 258 259 260 261 262 263
	diff_ns = timeval_to_ns(&tvblank) -
		  timeval_to_ns(&vblanktimestamp(dev, crtc, vblcount));

	/* If there is at least 1 msec difference between the last stored
	 * timestamp and tvblank, then we are currently executing our
	 * disable inside a new vblank interval, the tvblank timestamp
	 * corresponds to this new vblank interval and the irq handler
	 * for this vblank didn't run yet and won't run due to our disable.
	 * Therefore we need to do the job of drm_handle_vblank() and
	 * increment the vblank counter by one to account for this vblank.
	 *
	 * Skip this step if there isn't any high precision timestamp
	 * available. In that case we can't account for this and just
	 * hope for the best.
	 */
264 265
	if (vblrc && (abs64(diff_ns) > 1000000))
		store_vblank(dev, crtc, 1, &tvblank);
266 267 268 269

	spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
}

270 271
static void vblank_disable_fn(unsigned long arg)
{
272 273
	struct drm_vblank_crtc *vblank = (void *)arg;
	struct drm_device *dev = vblank->dev;
274
	unsigned long irqflags;
275
	int crtc = vblank->crtc;
276 277 278 279

	if (!dev->vblank_disable_allowed)
		return;

280 281 282 283
	spin_lock_irqsave(&dev->vbl_lock, irqflags);
	if (atomic_read(&vblank->refcount) == 0 && vblank->enabled) {
		DRM_DEBUG("disabling vblank on crtc %d\n", crtc);
		vblank_disable_and_save(dev, crtc);
284
	}
285
	spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
286 287
}

D
Daniel Vetter 已提交
288 289 290 291 292 293
/**
 * drm_vblank_cleanup - cleanup vblank support
 * @dev: DRM device
 *
 * This function cleans up any resources allocated in drm_vblank_init.
 */
294
void drm_vblank_cleanup(struct drm_device *dev)
295
{
296 297
	int crtc;

298 299 300 301
	/* Bail if the driver didn't call drm_vblank_init() */
	if (dev->num_crtcs == 0)
		return;

302
	for (crtc = 0; crtc < dev->num_crtcs; crtc++) {
303 304
		struct drm_vblank_crtc *vblank = &dev->vblank[crtc];

305 306
		WARN_ON(vblank->enabled &&
			drm_core_check_feature(dev, DRIVER_MODESET));
307

308
		del_timer_sync(&vblank->disable_timer);
309
	}
310

311
	kfree(dev->vblank);
312 313 314

	dev->num_crtcs = 0;
}
315
EXPORT_SYMBOL(drm_vblank_cleanup);
316

D
Daniel Vetter 已提交
317 318 319 320 321 322 323 324 325 326
/**
 * drm_vblank_init - initialize vblank support
 * @dev: drm_device
 * @num_crtcs: number of crtcs supported by @dev
 *
 * This function initializes vblank support for @num_crtcs display pipelines.
 *
 * Returns:
 * Zero on success or a negative error code on failure.
 */
327 328 329 330 331
int drm_vblank_init(struct drm_device *dev, int num_crtcs)
{
	int i, ret = -ENOMEM;

	spin_lock_init(&dev->vbl_lock);
332 333
	spin_lock_init(&dev->vblank_time_lock);

334 335
	dev->num_crtcs = num_crtcs;

336 337
	dev->vblank = kcalloc(num_crtcs, sizeof(*dev->vblank), GFP_KERNEL);
	if (!dev->vblank)
338 339
		goto err;

340
	for (i = 0; i < num_crtcs; i++) {
341 342 343 344 345 346 347
		struct drm_vblank_crtc *vblank = &dev->vblank[i];

		vblank->dev = dev;
		vblank->crtc = i;
		init_waitqueue_head(&vblank->queue);
		setup_timer(&vblank->disable_timer, vblank_disable_fn,
			    (unsigned long)vblank);
348
	}
349

350
	DRM_INFO("Supports vblank timestamp caching Rev 2 (21.10.2013).\n");
351 352 353 354 355 356 357

	/* Driver specific high-precision vblank timestamping supported? */
	if (dev->driver->get_vblank_timestamp)
		DRM_INFO("Driver supports precise vblank timestamp query.\n");
	else
		DRM_INFO("No driver support for vblank timestamp query.\n");

358 359 360 361 362 363 364
	/* Must have precise timestamping for reliable vblank instant disable */
	if (dev->vblank_disable_immediate && !dev->driver->get_vblank_timestamp) {
		dev->vblank_disable_immediate = false;
		DRM_INFO("Setting vblank_disable_immediate to false because "
			 "get_vblank_timestamp == NULL\n");
	}

365 366
	dev->vblank_disable_allowed = false;

367 368 369
	return 0;

err:
370
	dev->num_crtcs = 0;
371 372 373 374
	return ret;
}
EXPORT_SYMBOL(drm_vblank_init);

375 376 377 378 379 380 381 382 383 384 385 386
static void drm_irq_vgaarb_nokms(void *cookie, bool state)
{
	struct drm_device *dev = cookie;

	if (dev->driver->vgaarb_irq) {
		dev->driver->vgaarb_irq(dev, state);
		return;
	}

	if (!dev->irq_enabled)
		return;

387 388 389 390 391 392 393 394
	if (state) {
		if (dev->driver->irq_uninstall)
			dev->driver->irq_uninstall(dev);
	} else {
		if (dev->driver->irq_preinstall)
			dev->driver->irq_preinstall(dev);
		if (dev->driver->irq_postinstall)
			dev->driver->irq_postinstall(dev);
395 396 397
	}
}

L
Linus Torvalds 已提交
398
/**
D
Daniel Vetter 已提交
399 400 401
 * drm_irq_install - install IRQ handler
 * @dev: DRM device
 * @irq: IRQ number to install the handler for
L
Linus Torvalds 已提交
402
 *
403
 * Initializes the IRQ related data. Installs the handler, calling the driver
D
Daniel Vetter 已提交
404 405 406 407 408 409 410 411 412 413
 * irq_preinstall() and irq_postinstall() functions before and after the
 * installation.
 *
 * This is the simplified helper interface provided for drivers with no special
 * needs. Drivers which need to install interrupt handlers for multiple
 * interrupts must instead set drm_device->irq_enabled to signal the DRM core
 * that vblank interrupts are available.
 *
 * Returns:
 * Zero on success or a negative error code on failure.
L
Linus Torvalds 已提交
414
 */
415
int drm_irq_install(struct drm_device *dev, int irq)
L
Linus Torvalds 已提交
416
{
417
	int ret;
D
Dave Airlie 已提交
418
	unsigned long sh_flags = 0;
L
Linus Torvalds 已提交
419 420 421 422

	if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
		return -EINVAL;

423
	if (irq == 0)
L
Linus Torvalds 已提交
424 425 426
		return -EINVAL;

	/* Driver must have been initialized */
427
	if (!dev->dev_private)
L
Linus Torvalds 已提交
428 429
		return -EINVAL;

430
	if (dev->irq_enabled)
L
Linus Torvalds 已提交
431
		return -EBUSY;
V
Ville Syrjälä 已提交
432
	dev->irq_enabled = true;
L
Linus Torvalds 已提交
433

434
	DRM_DEBUG("irq=%d\n", irq);
L
Linus Torvalds 已提交
435

D
Dave Airlie 已提交
436
	/* Before installing handler */
437 438
	if (dev->driver->irq_preinstall)
		dev->driver->irq_preinstall(dev);
L
Linus Torvalds 已提交
439

D
Dave Airlie 已提交
440
	/* Install handler */
L
Linus Torvalds 已提交
441
	if (drm_core_check_feature(dev, DRIVER_IRQ_SHARED))
442
		sh_flags = IRQF_SHARED;
D
Dave Airlie 已提交
443

444
	ret = request_irq(irq, dev->driver->irq_handler,
D
Daniel Vetter 已提交
445
			  sh_flags, dev->driver->name, dev);
J
Jesse Barnes 已提交
446

D
Dave Airlie 已提交
447
	if (ret < 0) {
V
Ville Syrjälä 已提交
448
		dev->irq_enabled = false;
L
Linus Torvalds 已提交
449 450 451
		return ret;
	}

452 453 454
	if (!drm_core_check_feature(dev, DRIVER_MODESET))
		vga_client_register(dev->pdev, (void *)dev, drm_irq_vgaarb_nokms, NULL);

D
Dave Airlie 已提交
455
	/* After installing handler */
456 457 458
	if (dev->driver->irq_postinstall)
		ret = dev->driver->irq_postinstall(dev);

459
	if (ret < 0) {
V
Ville Syrjälä 已提交
460
		dev->irq_enabled = false;
461 462
		if (!drm_core_check_feature(dev, DRIVER_MODESET))
			vga_client_register(dev->pdev, NULL, NULL, NULL);
463 464 465
		free_irq(irq, dev);
	} else {
		dev->irq = irq;
466
	}
L
Linus Torvalds 已提交
467

468
	return ret;
L
Linus Torvalds 已提交
469
}
470
EXPORT_SYMBOL(drm_irq_install);
L
Linus Torvalds 已提交
471 472

/**
D
Daniel Vetter 已提交
473 474 475 476 477 478 479
 * drm_irq_uninstall - uninstall the IRQ handler
 * @dev: DRM device
 *
 * Calls the driver's irq_uninstall() function and unregisters the IRQ handler.
 * This should only be called by drivers which used drm_irq_install() to set up
 * their interrupt handler. Other drivers must only reset
 * drm_device->irq_enabled to false.
L
Linus Torvalds 已提交
480
 *
D
Daniel Vetter 已提交
481 482 483
 * Note that for kernel modesetting drivers it is a bug if this function fails.
 * The sanity checks are only to catch buggy user modesetting drivers which call
 * the same function through an ioctl.
L
Linus Torvalds 已提交
484
 *
D
Daniel Vetter 已提交
485 486
 * Returns:
 * Zero on success or a negative error code on failure.
L
Linus Torvalds 已提交
487
 */
488
int drm_irq_uninstall(struct drm_device *dev)
L
Linus Torvalds 已提交
489
{
490
	unsigned long irqflags;
V
Ville Syrjälä 已提交
491 492
	bool irq_enabled;
	int i;
L
Linus Torvalds 已提交
493 494 495 496 497

	if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
		return -EINVAL;

	irq_enabled = dev->irq_enabled;
V
Ville Syrjälä 已提交
498
	dev->irq_enabled = false;
L
Linus Torvalds 已提交
499

500
	/*
501 502 503 504
	 * Wake up any waiters so they don't hang. This is just to paper over
	 * isssues for UMS drivers which aren't in full control of their
	 * vblank/irq handling. KMS drivers must ensure that vblanks are all
	 * disabled when uninstalling the irq handler.
505
	 */
506 507 508
	if (dev->num_crtcs) {
		spin_lock_irqsave(&dev->vbl_lock, irqflags);
		for (i = 0; i < dev->num_crtcs; i++) {
509 510
			struct drm_vblank_crtc *vblank = &dev->vblank[i];

511 512 513 514 515 516
			if (!vblank->enabled)
				continue;

			WARN_ON(drm_core_check_feature(dev, DRIVER_MODESET));

			vblank_disable_and_save(dev, i);
517
			wake_up(&vblank->queue);
518 519
		}
		spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
520 521
	}

D
Dave Airlie 已提交
522
	if (!irq_enabled)
L
Linus Torvalds 已提交
523 524
		return -EINVAL;

525
	DRM_DEBUG("irq=%d\n", dev->irq);
L
Linus Torvalds 已提交
526

527 528 529
	if (!drm_core_check_feature(dev, DRIVER_MODESET))
		vga_client_register(dev->pdev, NULL, NULL, NULL);

530 531
	if (dev->driver->irq_uninstall)
		dev->driver->irq_uninstall(dev);
L
Linus Torvalds 已提交
532

533
	free_irq(dev->irq, dev);
L
Linus Torvalds 已提交
534 535 536 537 538

	return 0;
}
EXPORT_SYMBOL(drm_irq_uninstall);

D
Daniel Vetter 已提交
539
/*
L
Linus Torvalds 已提交
540 541 542
 * IRQ control ioctl.
 *
 * \param inode device inode.
543
 * \param file_priv DRM file private.
L
Linus Torvalds 已提交
544 545 546 547 548 549
 * \param cmd command.
 * \param arg user argument, pointing to a drm_control structure.
 * \return zero on success or a negative number on failure.
 *
 * Calls irq_install() or irq_uninstall() according to \p arg.
 */
550 551
int drm_control(struct drm_device *dev, void *data,
		struct drm_file *file_priv)
L
Linus Torvalds 已提交
552
{
553
	struct drm_control *ctl = data;
554
	int ret = 0, irq;
D
Dave Airlie 已提交
555

556 557 558
	/* if we haven't irq we fallback for compatibility reasons -
	 * this used to be a separate function in drm_dma.h
	 */
L
Linus Torvalds 已提交
559

560 561 562 563 564 565 566
	if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
		return 0;
	if (drm_core_check_feature(dev, DRIVER_MODESET))
		return 0;
	/* UMS was only ever support on pci devices. */
	if (WARN_ON(!dev->pdev))
		return -EINVAL;
L
Linus Torvalds 已提交
567

568
	switch (ctl->func) {
L
Linus Torvalds 已提交
569
	case DRM_INST_HANDLER:
570 571
		irq = dev->pdev->irq;

L
Linus Torvalds 已提交
572
		if (dev->if_version < DRM_IF_VERSION(1, 2) &&
573
		    ctl->irq != irq)
L
Linus Torvalds 已提交
574
			return -EINVAL;
575
		mutex_lock(&dev->struct_mutex);
576
		ret = drm_irq_install(dev, irq);
577 578 579
		mutex_unlock(&dev->struct_mutex);

		return ret;
L
Linus Torvalds 已提交
580
	case DRM_UNINST_HANDLER:
581 582 583 584 585
		mutex_lock(&dev->struct_mutex);
		ret = drm_irq_uninstall(dev);
		mutex_unlock(&dev->struct_mutex);

		return ret;
L
Linus Torvalds 已提交
586 587 588 589 590
	default:
		return -EINVAL;
	}
}

591
/**
D
Daniel Vetter 已提交
592 593 594
 * drm_calc_timestamping_constants - calculate vblank timestamp constants
 * @crtc: drm_crtc whose timestamp constants should be updated.
 * @mode: display mode containing the scanout timings
595
 *
596 597 598
 * Calculate and store various constants which are later
 * needed by vblank and swap-completion timestamping, e.g,
 * by drm_calc_vbltimestamp_from_scanoutpos(). They are
D
Daniel Vetter 已提交
599
 * derived from CRTC's true scanout timing, so they take
600
 * things like panel scaling or other adjustments into account.
601
 */
602 603
void drm_calc_timestamping_constants(struct drm_crtc *crtc,
				     const struct drm_display_mode *mode)
604
{
605
	int linedur_ns = 0, pixeldur_ns = 0, framedur_ns = 0;
606
	int dotclock = mode->crtc_clock;
607 608 609

	/* Valid dotclock? */
	if (dotclock > 0) {
610 611 612 613 614 615
		int frame_size = mode->crtc_htotal * mode->crtc_vtotal;

		/*
		 * Convert scanline length in pixels and video
		 * dot clock to line duration, frame duration
		 * and pixel duration in nanoseconds:
616
		 */
617 618 619
		pixeldur_ns = 1000000 / dotclock;
		linedur_ns  = div_u64((u64) mode->crtc_htotal * 1000000, dotclock);
		framedur_ns = div_u64((u64) frame_size * 1000000, dotclock);
620 621 622 623 624 625

		/*
		 * Fields of interlaced scanout modes are only half a frame duration.
		 */
		if (mode->flags & DRM_MODE_FLAG_INTERLACE)
			framedur_ns /= 2;
626 627 628 629 630 631 632 633 634
	} else
		DRM_ERROR("crtc %d: Can't calculate constants, dotclock = 0!\n",
			  crtc->base.id);

	crtc->pixeldur_ns = pixeldur_ns;
	crtc->linedur_ns  = linedur_ns;
	crtc->framedur_ns = framedur_ns;

	DRM_DEBUG("crtc %d: hwmode: htotal %d, vtotal %d, vdisplay %d\n",
635 636
		  crtc->base.id, mode->crtc_htotal,
		  mode->crtc_vtotal, mode->crtc_vdisplay);
637
	DRM_DEBUG("crtc %d: clock %d kHz framedur %d linedur %d, pixeldur %d\n",
638 639
		  crtc->base.id, dotclock, framedur_ns,
		  linedur_ns, pixeldur_ns);
640 641 642 643
}
EXPORT_SYMBOL(drm_calc_timestamping_constants);

/**
D
Daniel Vetter 已提交
644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659
 * drm_calc_vbltimestamp_from_scanoutpos - precise vblank timestamp helper
 * @dev: DRM device
 * @crtc: Which CRTC's vblank timestamp to retrieve
 * @max_error: Desired maximum allowable error in timestamps (nanosecs)
 *             On return contains true maximum error of timestamp
 * @vblank_time: Pointer to struct timeval which should receive the timestamp
 * @flags: Flags to pass to driver:
 *         0 = Default,
 *         DRM_CALLED_FROM_VBLIRQ = If function is called from vbl IRQ handler
 * @refcrtc: CRTC which defines scanout timing
 * @mode: mode which defines the scanout timings
 *
 * Implements calculation of exact vblank timestamps from given drm_display_mode
 * timings and current video scanout position of a CRTC. This can be called from
 * within get_vblank_timestamp() implementation of a kms driver to implement the
 * actual timestamping.
660 661 662 663 664 665 666 667 668 669 670 671 672 673
 *
 * Should return timestamps conforming to the OML_sync_control OpenML
 * extension specification. The timestamp corresponds to the end of
 * the vblank interval, aka start of scanout of topmost-leftmost display
 * pixel in the following video frame.
 *
 * Requires support for optional dev->driver->get_scanout_position()
 * in kms driver, plus a bit of setup code to provide a drm_display_mode
 * that corresponds to the true scanout timing.
 *
 * The current implementation only handles standard video modes. It
 * returns as no operation if a doublescan or interlaced video mode is
 * active. Higher level code is expected to handle this.
 *
D
Daniel Vetter 已提交
674 675
 * Returns:
 * Negative value on error, failure or if not supported in current
676 677
 * video mode:
 *
D
Daniel Vetter 已提交
678
 * -EINVAL   - Invalid CRTC.
679 680 681 682 683 684 685 686 687 688 689 690 691 692
 * -EAGAIN   - Temporary unavailable, e.g., called before initial modeset.
 * -ENOTSUPP - Function not supported in current display mode.
 * -EIO      - Failed, e.g., due to failed scanout position query.
 *
 * Returns or'ed positive status flags on success:
 *
 * DRM_VBLANKTIME_SCANOUTPOS_METHOD - Signal this method used for timestamping.
 * DRM_VBLANKTIME_INVBL - Timestamp taken while scanout was in vblank interval.
 *
 */
int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, int crtc,
					  int *max_error,
					  struct timeval *vblank_time,
					  unsigned flags,
693 694
					  const struct drm_crtc *refcrtc,
					  const struct drm_display_mode *mode)
695
{
696
	struct timeval tv_etime;
T
Thomas Gleixner 已提交
697
	ktime_t stime, etime;
698
	int vbl_status;
699
	int vpos, hpos, i;
700
	int framedur_ns, linedur_ns, pixeldur_ns, delta_ns, duration_ns;
701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721
	bool invbl;

	if (crtc < 0 || crtc >= dev->num_crtcs) {
		DRM_ERROR("Invalid crtc %d\n", crtc);
		return -EINVAL;
	}

	/* Scanout position query not supported? Should not happen. */
	if (!dev->driver->get_scanout_position) {
		DRM_ERROR("Called from driver w/o get_scanout_position()!?\n");
		return -EIO;
	}

	/* Durations of frames, lines, pixels in nanoseconds. */
	framedur_ns = refcrtc->framedur_ns;
	linedur_ns  = refcrtc->linedur_ns;
	pixeldur_ns = refcrtc->pixeldur_ns;

	/* If mode timing undefined, just return as no-op:
	 * Happens during initial modesetting of a crtc.
	 */
722
	if (framedur_ns == 0) {
723 724 725 726 727 728 729 730 731 732 733 734
		DRM_DEBUG("crtc %d: Noop due to uninitialized mode.\n", crtc);
		return -EAGAIN;
	}

	/* Get current scanout position with system timestamp.
	 * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times
	 * if single query takes longer than max_error nanoseconds.
	 *
	 * This guarantees a tight bound on maximum error if
	 * code gets preempted or delayed for some reason.
	 */
	for (i = 0; i < DRM_TIMESTAMP_MAXRETRIES; i++) {
735 736 737 738
		/*
		 * Get vertical and horizontal scanout position vpos, hpos,
		 * and bounding timestamps stime, etime, pre/post query.
		 */
739
		vbl_status = dev->driver->get_scanout_position(dev, crtc, flags, &vpos,
740
							       &hpos, &stime, &etime);
741 742 743 744 745 746 747 748

		/* Return as no-op if scanout query unsupported or failed. */
		if (!(vbl_status & DRM_SCANOUTPOS_VALID)) {
			DRM_DEBUG("crtc %d : scanoutpos query failed [%d].\n",
				  crtc, vbl_status);
			return -EIO;
		}

749
		/* Compute uncertainty in timestamp of scanout position query. */
750
		duration_ns = ktime_to_ns(etime) - ktime_to_ns(stime);
751 752

		/* Accept result with <  max_error nsecs timing uncertainty. */
753
		if (duration_ns <= *max_error)
754 755 756 757 758 759
			break;
	}

	/* Noisy system timing? */
	if (i == DRM_TIMESTAMP_MAXRETRIES) {
		DRM_DEBUG("crtc %d: Noisy timestamp %d us > %d us [%d reps].\n",
760
			  crtc, duration_ns/1000, *max_error/1000, i);
761 762 763
	}

	/* Return upper bound of timestamp precision error. */
764
	*max_error = duration_ns;
765 766 767 768 769 770

	/* Check if in vblank area:
	 * vpos is >=0 in video scanout area, but negative
	 * within vblank area, counting down the number of lines until
	 * start of scanout.
	 */
771
	invbl = vbl_status & DRM_SCANOUTPOS_IN_VBLANK;
772 773 774 775 776

	/* Convert scanout position into elapsed time at raw_time query
	 * since start of scanout at first display scanline. delta_ns
	 * can be negative if start of scanout hasn't happened yet.
	 */
777
	delta_ns = vpos * linedur_ns + hpos * pixeldur_ns;
778

779
	if (!drm_timestamp_monotonic)
T
Thomas Gleixner 已提交
780
		etime = ktime_mono_to_real(etime);
781

782 783
	/* save this only for debugging purposes */
	tv_etime = ktime_to_timeval(etime);
784 785 786
	/* Subtract time delta from raw timestamp to get final
	 * vblank_time timestamp for end of vblank.
	 */
787 788 789 790
	if (delta_ns < 0)
		etime = ktime_add_ns(etime, -delta_ns);
	else
		etime = ktime_sub_ns(etime, delta_ns);
791
	*vblank_time = ktime_to_timeval(etime);
792

793 794
	DRM_DEBUG("crtc %d : v %d p(%d,%d)@ %ld.%ld -> %ld.%ld [e %d us, %d rep]\n",
		  crtc, (int)vbl_status, hpos, vpos,
795
		  (long)tv_etime.tv_sec, (long)tv_etime.tv_usec,
796
		  (long)vblank_time->tv_sec, (long)vblank_time->tv_usec,
797
		  duration_ns/1000, i);
798 799 800

	vbl_status = DRM_VBLANKTIME_SCANOUTPOS_METHOD;
	if (invbl)
801
		vbl_status |= DRM_VBLANKTIME_IN_VBLANK;
802 803 804 805 806

	return vbl_status;
}
EXPORT_SYMBOL(drm_calc_vbltimestamp_from_scanoutpos);

807 808 809 810
static struct timeval get_drm_timestamp(void)
{
	ktime_t now;

T
Thomas Gleixner 已提交
811
	now = drm_timestamp_monotonic ? ktime_get() : ktime_get_real();
812 813 814
	return ktime_to_timeval(now);
}

815 816
/**
 * drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent
817
 *                             vblank interval
818
 * @dev: DRM device
D
Daniel Vetter 已提交
819
 * @crtc: which CRTC's vblank timestamp to retrieve
820 821
 * @tvblank: Pointer to target struct timeval which should receive the timestamp
 * @flags: Flags to pass to driver:
D
Daniel Vetter 已提交
822 823
 *         0 = Default,
 *         DRM_CALLED_FROM_VBLIRQ = If function is called from vbl IRQ handler
824 825
 *
 * Fetches the system timestamp corresponding to the time of the most recent
D
Daniel Vetter 已提交
826
 * vblank interval on specified CRTC. May call into kms-driver to
827 828 829 830 831
 * compute the timestamp with a high-precision GPU specific method.
 *
 * Returns zero if timestamp originates from uncorrected do_gettimeofday()
 * call, i.e., it isn't very precisely locked to the true vblank.
 *
D
Daniel Vetter 已提交
832
 * Returns:
833
 * True if timestamp is considered to be very precise, false otherwise.
834
 */
835 836 837
static bool
drm_get_last_vbltimestamp(struct drm_device *dev, int crtc,
			  struct timeval *tvblank, unsigned flags)
838
{
839
	int ret;
840 841 842 843 844 845 846 847 848

	/* Define requested maximum error on timestamps (nanoseconds). */
	int max_error = (int) drm_timestamp_precision * 1000;

	/* Query driver if possible and precision timestamping enabled. */
	if (dev->driver->get_vblank_timestamp && (max_error > 0)) {
		ret = dev->driver->get_vblank_timestamp(dev, crtc, &max_error,
							tvblank, flags);
		if (ret > 0)
849
			return true;
850 851 852
	}

	/* GPU high precision timestamp query unsupported or failed.
853
	 * Return current monotonic/gettimeofday timestamp as best estimate.
854
	 */
855
	*tvblank = get_drm_timestamp();
856

857
	return false;
858 859
}

860 861 862 863 864 865 866 867
/**
 * drm_vblank_count - retrieve "cooked" vblank counter value
 * @dev: DRM device
 * @crtc: which counter to retrieve
 *
 * Fetches the "cooked" vblank count value that represents the number of
 * vblank events since the system was booted, including lost events due to
 * modesetting activity.
D
Daniel Vetter 已提交
868
 *
869 870
 * This is the legacy version of drm_crtc_vblank_count().
 *
D
Daniel Vetter 已提交
871 872
 * Returns:
 * The software vblank counter.
873 874 875
 */
u32 drm_vblank_count(struct drm_device *dev, int crtc)
{
876 877
	struct drm_vblank_crtc *vblank = &dev->vblank[crtc];

R
Rob Clark 已提交
878 879
	if (WARN_ON(crtc >= dev->num_crtcs))
		return 0;
880

881
	return vblank->count;
882 883 884
}
EXPORT_SYMBOL(drm_vblank_count);

885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903
/**
 * drm_crtc_vblank_count - retrieve "cooked" vblank counter value
 * @crtc: which counter to retrieve
 *
 * Fetches the "cooked" vblank count value that represents the number of
 * vblank events since the system was booted, including lost events due to
 * modesetting activity.
 *
 * This is the native KMS version of drm_vblank_count().
 *
 * Returns:
 * The software vblank counter.
 */
u32 drm_crtc_vblank_count(struct drm_crtc *crtc)
{
	return drm_vblank_count(crtc->dev, drm_crtc_index(crtc));
}
EXPORT_SYMBOL(drm_crtc_vblank_count);

904 905 906 907 908 909 910 911 912 913 914
/**
 * drm_vblank_count_and_time - retrieve "cooked" vblank counter value
 * and the system timestamp corresponding to that vblank counter value.
 *
 * @dev: DRM device
 * @crtc: which counter to retrieve
 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
 *
 * Fetches the "cooked" vblank count value that represents the number of
 * vblank events since the system was booted, including lost events due to
 * modesetting activity. Returns corresponding system timestamp of the time
D
Daniel Vetter 已提交
915
 * of the vblank interval that corresponds to the current vblank counter value.
916 917 918 919
 */
u32 drm_vblank_count_and_time(struct drm_device *dev, int crtc,
			      struct timeval *vblanktime)
{
920
	struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
921 922
	u32 cur_vblank;

R
Rob Clark 已提交
923 924 925
	if (WARN_ON(crtc >= dev->num_crtcs))
		return 0;

926 927 928 929
	/*
	 * Vblank timestamps are read lockless. To ensure consistency the vblank
	 * counter is rechecked and ordering is ensured using memory barriers.
	 * This works like a seqlock. The write-side barriers are in store_vblank.
930 931
	 */
	do {
932 933
		cur_vblank = vblank->count;
		smp_rmb();
934 935
		*vblanktime = vblanktimestamp(dev, crtc, cur_vblank);
		smp_rmb();
936
	} while (cur_vblank != vblank->count);
937 938 939 940 941

	return cur_vblank;
}
EXPORT_SYMBOL(drm_vblank_count_and_time);

942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965
static void send_vblank_event(struct drm_device *dev,
		struct drm_pending_vblank_event *e,
		unsigned long seq, struct timeval *now)
{
	WARN_ON_SMP(!spin_is_locked(&dev->event_lock));
	e->event.sequence = seq;
	e->event.tv_sec = now->tv_sec;
	e->event.tv_usec = now->tv_usec;

	list_add_tail(&e->base.link,
		      &e->base.file_priv->event_list);
	wake_up_interruptible(&e->base.file_priv->event_wait);
	trace_drm_vblank_event_delivered(e->base.pid, e->pipe,
					 e->event.sequence);
}

/**
 * drm_send_vblank_event - helper to send vblank event after pageflip
 * @dev: DRM device
 * @crtc: CRTC in question
 * @e: the event to send
 *
 * Updates sequence # and timestamp on event, and sends it to userspace.
 * Caller must hold event lock.
966 967
 *
 * This is the legacy version of drm_crtc_send_vblank_event().
968 969 970 971 972 973
 */
void drm_send_vblank_event(struct drm_device *dev, int crtc,
		struct drm_pending_vblank_event *e)
{
	struct timeval now;
	unsigned int seq;
974

975
	if (dev->num_crtcs > 0) {
976 977 978
		seq = drm_vblank_count_and_time(dev, crtc, &now);
	} else {
		seq = 0;
979 980

		now = get_drm_timestamp();
981
	}
982
	e->pipe = crtc;
983 984 985 986
	send_vblank_event(dev, e, seq, &now);
}
EXPORT_SYMBOL(drm_send_vblank_event);

987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003
/**
 * drm_crtc_send_vblank_event - helper to send vblank event after pageflip
 * @crtc: the source CRTC of the vblank event
 * @e: the event to send
 *
 * Updates sequence # and timestamp on event, and sends it to userspace.
 * Caller must hold event lock.
 *
 * This is the native KMS version of drm_send_vblank_event().
 */
void drm_crtc_send_vblank_event(struct drm_crtc *crtc,
				struct drm_pending_vblank_event *e)
{
	drm_send_vblank_event(crtc->dev, drm_crtc_index(crtc), e);
}
EXPORT_SYMBOL(drm_crtc_send_vblank_event);

V
Ville Syrjälä 已提交
1004 1005 1006 1007 1008 1009 1010
/**
 * drm_vblank_enable - enable the vblank interrupt on a CRTC
 * @dev: DRM device
 * @crtc: CRTC in question
 */
static int drm_vblank_enable(struct drm_device *dev, int crtc)
{
1011
	struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
V
Ville Syrjälä 已提交
1012 1013 1014 1015 1016 1017
	int ret = 0;

	assert_spin_locked(&dev->vbl_lock);

	spin_lock(&dev->vblank_time_lock);

1018
	if (!vblank->enabled) {
D
Daniel Vetter 已提交
1019 1020
		/*
		 * Enable vblank irqs under vblank_time_lock protection.
V
Ville Syrjälä 已提交
1021 1022 1023 1024 1025 1026 1027 1028
		 * All vblank count & timestamp updates are held off
		 * until we are done reinitializing master counter and
		 * timestamps. Filtercode in drm_handle_vblank() will
		 * prevent double-accounting of same vblank interval.
		 */
		ret = dev->driver->enable_vblank(dev, crtc);
		DRM_DEBUG("enabling vblank on crtc %d, ret: %d\n", crtc, ret);
		if (ret)
1029
			atomic_dec(&vblank->refcount);
V
Ville Syrjälä 已提交
1030
		else {
1031
			vblank->enabled = true;
V
Ville Syrjälä 已提交
1032 1033 1034 1035 1036 1037 1038 1039 1040
			drm_update_vblank_count(dev, crtc);
		}
	}

	spin_unlock(&dev->vblank_time_lock);

	return ret;
}

1041 1042 1043 1044 1045 1046 1047 1048
/**
 * drm_vblank_get - get a reference count on vblank events
 * @dev: DRM device
 * @crtc: which CRTC to own
 *
 * Acquire a reference count on vblank events to avoid having them disabled
 * while in use.
 *
1049 1050
 * This is the legacy version of drm_crtc_vblank_get().
 *
D
Daniel Vetter 已提交
1051
 * Returns:
1052 1053 1054 1055
 * Zero on success, nonzero on failure.
 */
int drm_vblank_get(struct drm_device *dev, int crtc)
{
1056
	struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
1057
	unsigned long irqflags;
1058 1059
	int ret = 0;

1060 1061 1062
	if (!dev->num_crtcs)
		return -EINVAL;

R
Rob Clark 已提交
1063 1064 1065
	if (WARN_ON(crtc >= dev->num_crtcs))
		return -EINVAL;

1066 1067
	spin_lock_irqsave(&dev->vbl_lock, irqflags);
	/* Going from 0->1 means we have to enable interrupts again */
1068
	if (atomic_add_return(1, &vblank->refcount) == 1) {
V
Ville Syrjälä 已提交
1069
		ret = drm_vblank_enable(dev, crtc);
1070
	} else {
1071 1072
		if (!vblank->enabled) {
			atomic_dec(&vblank->refcount);
1073
			ret = -EINVAL;
1074 1075 1076 1077 1078 1079 1080 1081
		}
	}
	spin_unlock_irqrestore(&dev->vbl_lock, irqflags);

	return ret;
}
EXPORT_SYMBOL(drm_vblank_get);

1082 1083 1084 1085 1086 1087 1088
/**
 * drm_crtc_vblank_get - get a reference count on vblank events
 * @crtc: which CRTC to own
 *
 * Acquire a reference count on vblank events to avoid having them disabled
 * while in use.
 *
1089
 * This is the native kms version of drm_vblank_get().
1090 1091 1092 1093 1094 1095 1096 1097 1098 1099
 *
 * Returns:
 * Zero on success, nonzero on failure.
 */
int drm_crtc_vblank_get(struct drm_crtc *crtc)
{
	return drm_vblank_get(crtc->dev, drm_crtc_index(crtc));
}
EXPORT_SYMBOL(drm_crtc_vblank_get);

1100 1101 1102 1103 1104 1105
/**
 * drm_vblank_put - give up ownership of vblank events
 * @dev: DRM device
 * @crtc: which counter to give up
 *
 * Release ownership of a given vblank counter, turning off interrupts
1106
 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
1107 1108
 *
 * This is the legacy version of drm_crtc_vblank_put().
1109 1110 1111
 */
void drm_vblank_put(struct drm_device *dev, int crtc)
{
1112 1113
	struct drm_vblank_crtc *vblank = &dev->vblank[crtc];

1114
	if (WARN_ON(crtc >= dev->num_crtcs))
R
Rob Clark 已提交
1115
		return;
1116

1117
	if (WARN_ON(atomic_read(&vblank->refcount) == 0))
R
Rob Clark 已提交
1118 1119
		return;

1120
	/* Last user schedules interrupt disable */
1121
	if (atomic_dec_and_test(&vblank->refcount)) {
1122 1123 1124
		if (drm_vblank_offdelay == 0)
			return;
		else if (dev->vblank_disable_immediate || drm_vblank_offdelay < 0)
1125
			vblank_disable_fn((unsigned long)vblank);
1126
		else
1127 1128 1129
			mod_timer(&vblank->disable_timer,
				  jiffies + ((drm_vblank_offdelay * HZ)/1000));
	}
1130 1131 1132
}
EXPORT_SYMBOL(drm_vblank_put);

1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147
/**
 * drm_crtc_vblank_put - give up ownership of vblank events
 * @crtc: which counter to give up
 *
 * Release ownership of a given vblank counter, turning off interrupts
 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
 *
 * This is the native kms version of drm_vblank_put().
 */
void drm_crtc_vblank_put(struct drm_crtc *crtc)
{
	drm_vblank_put(crtc->dev, drm_crtc_index(crtc));
}
EXPORT_SYMBOL(drm_crtc_vblank_put);

1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161
/**
 * drm_wait_one_vblank - wait for one vblank
 * @dev: DRM device
 * @crtc: crtc index
 *
 * This waits for one vblank to pass on @crtc, using the irq driver interfaces.
 * It is a failure to call this when the vblank irq for @crtc is disabled, e.g.
 * due to lack of driver support or because the crtc is off.
 */
void drm_wait_one_vblank(struct drm_device *dev, int crtc)
{
	int ret;
	u32 last;

1162 1163 1164
	if (WARN_ON(crtc >= dev->num_crtcs))
		return;

1165
	ret = drm_vblank_get(dev, crtc);
1166
	if (WARN(ret, "vblank not available on crtc %i, ret=%i\n", crtc, ret))
1167 1168 1169 1170 1171 1172 1173 1174
		return;

	last = drm_vblank_count(dev, crtc);

	ret = wait_event_timeout(dev->vblank[crtc].queue,
				 last != drm_vblank_count(dev, crtc),
				 msecs_to_jiffies(100));

1175
	WARN(ret == 0, "vblank wait timed out on crtc %i\n", crtc);
1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194

	drm_vblank_put(dev, crtc);
}
EXPORT_SYMBOL(drm_wait_one_vblank);

/**
 * drm_crtc_wait_one_vblank - wait for one vblank
 * @crtc: DRM crtc
 *
 * This waits for one vblank to pass on @crtc, using the irq driver interfaces.
 * It is a failure to call this when the vblank irq for @crtc is disabled, e.g.
 * due to lack of driver support or because the crtc is off.
 */
void drm_crtc_wait_one_vblank(struct drm_crtc *crtc)
{
	drm_wait_one_vblank(crtc->dev, drm_crtc_index(crtc));
}
EXPORT_SYMBOL(drm_crtc_wait_one_vblank);

1195 1196 1197 1198 1199
/**
 * drm_vblank_off - disable vblank events on a CRTC
 * @dev: DRM device
 * @crtc: CRTC in question
 *
D
Daniel Vetter 已提交
1200 1201 1202 1203 1204 1205
 * Drivers can use this function to shut down the vblank interrupt handling when
 * disabling a crtc. This function ensures that the latest vblank frame count is
 * stored so that drm_vblank_on() can restore it again.
 *
 * Drivers must use this function when the hardware vblank counter can get
 * reset, e.g. when suspending.
1206 1207
 *
 * This is the legacy version of drm_crtc_vblank_off().
1208
 */
1209 1210
void drm_vblank_off(struct drm_device *dev, int crtc)
{
1211
	struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
1212 1213
	struct drm_pending_vblank_event *e, *t;
	struct timeval now;
1214
	unsigned long irqflags;
1215
	unsigned int seq;
1216

R
Rob Clark 已提交
1217 1218 1219
	if (WARN_ON(crtc >= dev->num_crtcs))
		return;

1220 1221 1222
	spin_lock_irqsave(&dev->event_lock, irqflags);

	spin_lock(&dev->vbl_lock);
1223
	vblank_disable_and_save(dev, crtc);
1224
	wake_up(&vblank->queue);
1225

1226 1227 1228 1229 1230 1231 1232 1233 1234 1235
	/*
	 * Prevent subsequent drm_vblank_get() from re-enabling
	 * the vblank interrupt by bumping the refcount.
	 */
	if (!vblank->inmodeset) {
		atomic_inc(&vblank->refcount);
		vblank->inmodeset = 1;
	}
	spin_unlock(&dev->vbl_lock);

1236 1237
	/* Send any queued vblank events, lest the natives grow disquiet */
	seq = drm_vblank_count_and_time(dev, crtc, &now);
1238

1239 1240 1241 1242 1243 1244
	list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
		if (e->pipe != crtc)
			continue;
		DRM_DEBUG("Sending premature vblank event on disable: \
			  wanted %d, current %d\n",
			  e->event.sequence, seq);
1245
		list_del(&e->base.link);
1246
		drm_vblank_put(dev, e->pipe);
1247
		send_vblank_event(dev, e, seq, &now);
1248
	}
1249
	spin_unlock_irqrestore(&dev->event_lock, irqflags);
1250 1251 1252
}
EXPORT_SYMBOL(drm_vblank_off);

1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271
/**
 * drm_crtc_vblank_off - disable vblank events on a CRTC
 * @crtc: CRTC in question
 *
 * Drivers can use this function to shut down the vblank interrupt handling when
 * disabling a crtc. This function ensures that the latest vblank frame count is
 * stored so that drm_vblank_on can restore it again.
 *
 * Drivers must use this function when the hardware vblank counter can get
 * reset, e.g. when suspending.
 *
 * This is the native kms version of drm_vblank_off().
 */
void drm_crtc_vblank_off(struct drm_crtc *crtc)
{
	drm_vblank_off(crtc->dev, drm_crtc_index(crtc));
}
EXPORT_SYMBOL(drm_crtc_vblank_off);

1272 1273
/**
 * drm_crtc_vblank_reset - reset vblank state to off on a CRTC
1274
 * @drm_crtc: CRTC in question
1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303
 *
 * Drivers can use this function to reset the vblank state to off at load time.
 * Drivers should use this together with the drm_crtc_vblank_off() and
 * drm_crtc_vblank_on() functions. The difference compared to
 * drm_crtc_vblank_off() is that this function doesn't save the vblank counter
 * and hence doesn't need to call any driver hooks.
 */
void drm_crtc_vblank_reset(struct drm_crtc *drm_crtc)
{
	struct drm_device *dev = drm_crtc->dev;
	unsigned long irqflags;
	int crtc = drm_crtc_index(drm_crtc);
	struct drm_vblank_crtc *vblank = &dev->vblank[crtc];

	spin_lock_irqsave(&dev->vbl_lock, irqflags);
	/*
	 * Prevent subsequent drm_vblank_get() from enabling the vblank
	 * interrupt by bumping the refcount.
	 */
	if (!vblank->inmodeset) {
		atomic_inc(&vblank->refcount);
		vblank->inmodeset = 1;
	}
	spin_unlock_irqrestore(&dev->vbl_lock, irqflags);

	WARN_ON(!list_empty(&dev->vblank_event_list));
}
EXPORT_SYMBOL(drm_crtc_vblank_reset);

V
Ville Syrjälä 已提交
1304 1305 1306 1307
/**
 * drm_vblank_on - enable vblank events on a CRTC
 * @dev: DRM device
 * @crtc: CRTC in question
D
Daniel Vetter 已提交
1308 1309 1310
 *
 * This functions restores the vblank interrupt state captured with
 * drm_vblank_off() again. Note that calls to drm_vblank_on() and
1311
 * drm_vblank_off() can be unbalanced and so can also be unconditionally called
D
Daniel Vetter 已提交
1312
 * in driver load code to reflect the current hardware state of the crtc.
1313 1314
 *
 * This is the legacy version of drm_crtc_vblank_on().
V
Ville Syrjälä 已提交
1315 1316 1317
 */
void drm_vblank_on(struct drm_device *dev, int crtc)
{
1318
	struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
V
Ville Syrjälä 已提交
1319 1320
	unsigned long irqflags;

R
Rob Clark 已提交
1321 1322 1323
	if (WARN_ON(crtc >= dev->num_crtcs))
		return;

V
Ville Syrjälä 已提交
1324
	spin_lock_irqsave(&dev->vbl_lock, irqflags);
1325
	/* Drop our private "prevent drm_vblank_get" refcount */
1326 1327 1328
	if (vblank->inmodeset) {
		atomic_dec(&vblank->refcount);
		vblank->inmodeset = 0;
1329
	}
1330 1331 1332 1333 1334 1335 1336 1337

	/*
	 * sample the current counter to avoid random jumps
	 * when drm_vblank_enable() applies the diff
	 *
	 * -1 to make sure user will never see the same
	 * vblank counter value before and after a modeset
	 */
1338
	vblank->last =
1339 1340
		(dev->driver->get_vblank_counter(dev, crtc) - 1) &
		dev->max_vblank_count;
1341 1342 1343 1344 1345 1346
	/*
	 * re-enable interrupts if there are users left, or the
	 * user wishes vblank interrupts to be enabled all the time.
	 */
	if (atomic_read(&vblank->refcount) != 0 ||
	    (!dev->vblank_disable_immediate && drm_vblank_offdelay == 0))
V
Ville Syrjälä 已提交
1347 1348 1349 1350 1351
		WARN_ON(drm_vblank_enable(dev, crtc));
	spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
}
EXPORT_SYMBOL(drm_vblank_on);

1352 1353 1354 1355 1356 1357
/**
 * drm_crtc_vblank_on - enable vblank events on a CRTC
 * @crtc: CRTC in question
 *
 * This functions restores the vblank interrupt state captured with
 * drm_vblank_off() again. Note that calls to drm_vblank_on() and
1358
 * drm_vblank_off() can be unbalanced and so can also be unconditionally called
1359 1360 1361 1362 1363 1364 1365 1366 1367 1368
 * in driver load code to reflect the current hardware state of the crtc.
 *
 * This is the native kms version of drm_vblank_on().
 */
void drm_crtc_vblank_on(struct drm_crtc *crtc)
{
	drm_vblank_on(crtc->dev, drm_crtc_index(crtc));
}
EXPORT_SYMBOL(drm_crtc_vblank_on);

D
Dave Airlie 已提交
1369 1370 1371 1372 1373 1374 1375
/**
 * drm_vblank_pre_modeset - account for vblanks across mode sets
 * @dev: DRM device
 * @crtc: CRTC in question
 *
 * Account for vblank events across mode setting events, which will likely
 * reset the hardware frame counter.
D
Daniel Vetter 已提交
1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390
 *
 * This is done by grabbing a temporary vblank reference to ensure that the
 * vblank interrupt keeps running across the modeset sequence. With this the
 * software-side vblank frame counting will ensure that there are no jumps or
 * discontinuities.
 *
 * Unfortunately this approach is racy and also doesn't work when the vblank
 * interrupt stops running, e.g. across system suspend resume. It is therefore
 * highly recommended that drivers use the newer drm_vblank_off() and
 * drm_vblank_on() instead. drm_vblank_pre_modeset() only works correctly when
 * using "cooked" software vblank frame counters and not relying on any hardware
 * counters.
 *
 * Drivers must call drm_vblank_post_modeset() when re-enabling the same crtc
 * again.
D
Dave Airlie 已提交
1391 1392 1393
 */
void drm_vblank_pre_modeset(struct drm_device *dev, int crtc)
{
1394 1395
	struct drm_vblank_crtc *vblank = &dev->vblank[crtc];

1396
	/* vblank is not initialized (IRQ not installed ?), or has been freed */
1397 1398
	if (!dev->num_crtcs)
		return;
R
Rob Clark 已提交
1399 1400 1401 1402

	if (WARN_ON(crtc >= dev->num_crtcs))
		return;

D
Dave Airlie 已提交
1403 1404 1405 1406 1407 1408 1409
	/*
	 * To avoid all the problems that might happen if interrupts
	 * were enabled/disabled around or between these calls, we just
	 * have the kernel take a reference on the CRTC (just once though
	 * to avoid corrupting the count if multiple, mismatch calls occur),
	 * so that interrupts remain enabled in the interim.
	 */
1410 1411
	if (!vblank->inmodeset) {
		vblank->inmodeset = 0x1;
1412
		if (drm_vblank_get(dev, crtc) == 0)
1413
			vblank->inmodeset |= 0x2;
D
Dave Airlie 已提交
1414 1415 1416 1417
	}
}
EXPORT_SYMBOL(drm_vblank_pre_modeset);

D
Daniel Vetter 已提交
1418 1419 1420 1421 1422 1423 1424 1425
/**
 * drm_vblank_post_modeset - undo drm_vblank_pre_modeset changes
 * @dev: DRM device
 * @crtc: CRTC in question
 *
 * This function again drops the temporary vblank reference acquired in
 * drm_vblank_pre_modeset.
 */
D
Dave Airlie 已提交
1426 1427
void drm_vblank_post_modeset(struct drm_device *dev, int crtc)
{
1428
	struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
D
Dave Airlie 已提交
1429 1430
	unsigned long irqflags;

1431 1432 1433 1434
	/* vblank is not initialized (IRQ not installed ?), or has been freed */
	if (!dev->num_crtcs)
		return;

1435 1436 1437
	if (WARN_ON(crtc >= dev->num_crtcs))
		return;

1438
	if (vblank->inmodeset) {
D
Dave Airlie 已提交
1439
		spin_lock_irqsave(&dev->vbl_lock, irqflags);
1440
		dev->vblank_disable_allowed = true;
D
Dave Airlie 已提交
1441
		spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1442

1443
		if (vblank->inmodeset & 0x2)
1444 1445
			drm_vblank_put(dev, crtc);

1446
		vblank->inmodeset = 0;
D
Dave Airlie 已提交
1447 1448 1449 1450
	}
}
EXPORT_SYMBOL(drm_vblank_post_modeset);

D
Daniel Vetter 已提交
1451
/*
1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465
 * drm_modeset_ctl - handle vblank event counter changes across mode switch
 * @DRM_IOCTL_ARGS: standard ioctl arguments
 *
 * Applications should call the %_DRM_PRE_MODESET and %_DRM_POST_MODESET
 * ioctls around modesetting so that any lost vblank events are accounted for.
 *
 * Generally the counter will reset across mode sets.  If interrupts are
 * enabled around this call, we don't have to do anything since the counter
 * will have already been incremented.
 */
int drm_modeset_ctl(struct drm_device *dev, void *data,
		    struct drm_file *file_priv)
{
	struct drm_modeset_ctl *modeset = data;
1466
	unsigned int crtc;
1467 1468 1469

	/* If drm_vblank_init() hasn't been called yet, just no-op */
	if (!dev->num_crtcs)
1470
		return 0;
1471

1472 1473 1474 1475
	/* KMS drivers handle this internally */
	if (drm_core_check_feature(dev, DRIVER_MODESET))
		return 0;

1476
	crtc = modeset->crtc;
1477 1478
	if (crtc >= dev->num_crtcs)
		return -EINVAL;
1479 1480 1481

	switch (modeset->cmd) {
	case _DRM_PRE_MODESET:
D
Dave Airlie 已提交
1482
		drm_vblank_pre_modeset(dev, crtc);
1483 1484
		break;
	case _DRM_POST_MODESET:
D
Dave Airlie 已提交
1485
		drm_vblank_post_modeset(dev, crtc);
1486 1487
		break;
	default:
1488
		return -EINVAL;
1489 1490
	}

1491
	return 0;
1492 1493
}

1494 1495 1496 1497
static int drm_queue_vblank_event(struct drm_device *dev, int pipe,
				  union drm_wait_vblank *vblwait,
				  struct drm_file *file_priv)
{
1498
	struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1499 1500 1501 1502
	struct drm_pending_vblank_event *e;
	struct timeval now;
	unsigned long flags;
	unsigned int seq;
1503
	int ret;
1504

1505
	e = kzalloc(sizeof(*e), GFP_KERNEL);
1506 1507 1508 1509
	if (e == NULL) {
		ret = -ENOMEM;
		goto err_put;
	}
1510 1511

	e->pipe = pipe;
1512
	e->base.pid = current->pid;
1513
	e->event.base.type = DRM_EVENT_VBLANK;
1514
	e->event.base.length = sizeof(e->event);
1515 1516 1517 1518 1519 1520 1521
	e->event.user_data = vblwait->request.signal;
	e->base.event = &e->event.base;
	e->base.file_priv = file_priv;
	e->base.destroy = (void (*) (struct drm_pending_event *)) kfree;

	spin_lock_irqsave(&dev->event_lock, flags);

1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533
	/*
	 * drm_vblank_off() might have been called after we called
	 * drm_vblank_get(). drm_vblank_off() holds event_lock
	 * around the vblank disable, so no need for further locking.
	 * The reference from drm_vblank_get() protects against
	 * vblank disable from another source.
	 */
	if (!vblank->enabled) {
		ret = -EINVAL;
		goto err_unlock;
	}

1534
	if (file_priv->event_space < sizeof(e->event)) {
1535 1536
		ret = -EBUSY;
		goto err_unlock;
1537 1538
	}

1539
	file_priv->event_space -= sizeof(e->event);
1540 1541
	seq = drm_vblank_count_and_time(dev, pipe, &now);

1542 1543 1544
	if ((vblwait->request.type & _DRM_VBLANK_NEXTONMISS) &&
	    (seq - vblwait->request.sequence) <= (1 << 23)) {
		vblwait->request.sequence = seq + 1;
1545
		vblwait->reply.sequence = vblwait->request.sequence;
1546 1547 1548 1549 1550
	}

	DRM_DEBUG("event on vblank count %d, current %d, crtc %d\n",
		  vblwait->request.sequence, seq, pipe);

1551 1552 1553
	trace_drm_vblank_event_queued(current->pid, pipe,
				      vblwait->request.sequence);

1554 1555
	e->event.sequence = vblwait->request.sequence;
	if ((seq - vblwait->request.sequence) <= (1 << 23)) {
1556
		drm_vblank_put(dev, pipe);
1557
		send_vblank_event(dev, e, seq, &now);
1558
		vblwait->reply.sequence = seq;
1559
	} else {
1560
		/* drm_handle_vblank_events will call drm_vblank_put */
1561
		list_add_tail(&e->base.link, &dev->vblank_event_list);
1562
		vblwait->reply.sequence = vblwait->request.sequence;
1563 1564 1565 1566 1567
	}

	spin_unlock_irqrestore(&dev->event_lock, flags);

	return 0;
1568 1569 1570 1571 1572

err_unlock:
	spin_unlock_irqrestore(&dev->event_lock, flags);
	kfree(e);
err_put:
1573
	drm_vblank_put(dev, pipe);
1574
	return ret;
1575 1576
}

D
Daniel Vetter 已提交
1577
/*
L
Linus Torvalds 已提交
1578 1579 1580
 * Wait for VBLANK.
 *
 * \param inode device inode.
1581
 * \param file_priv DRM file private.
L
Linus Torvalds 已提交
1582 1583 1584 1585
 * \param cmd command.
 * \param data user argument, pointing to a drm_wait_vblank structure.
 * \return zero on success or a negative number on failure.
 *
1586 1587
 * This function enables the vblank interrupt on the pipe requested, then
 * sleeps waiting for the requested sequence number to occur, and drops
D
Daniel Vetter 已提交
1588
 * the vblank interrupt refcount afterwards. (vblank IRQ disable follows that
1589
 * after a timeout with no further vblank waits scheduled).
L
Linus Torvalds 已提交
1590
 */
1591 1592
int drm_wait_vblank(struct drm_device *dev, void *data,
		    struct drm_file *file_priv)
L
Linus Torvalds 已提交
1593
{
1594
	struct drm_vblank_crtc *vblank;
1595
	union drm_wait_vblank *vblwait = data;
1596
	int ret;
1597
	unsigned int flags, seq, crtc, high_crtc;
L
Linus Torvalds 已提交
1598

1599 1600
	if (!dev->irq_enabled)
		return -EINVAL;
L
Linus Torvalds 已提交
1601

1602 1603 1604
	if (vblwait->request.type & _DRM_VBLANK_SIGNAL)
		return -EINVAL;

1605
	if (vblwait->request.type &
1606 1607
	    ~(_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
	      _DRM_VBLANK_HIGH_CRTC_MASK)) {
1608
		DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
1609
			  vblwait->request.type,
1610 1611
			  (_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
			   _DRM_VBLANK_HIGH_CRTC_MASK));
1612 1613 1614
		return -EINVAL;
	}

1615
	flags = vblwait->request.type & _DRM_VBLANK_FLAGS_MASK;
1616 1617 1618 1619 1620
	high_crtc = (vblwait->request.type & _DRM_VBLANK_HIGH_CRTC_MASK);
	if (high_crtc)
		crtc = high_crtc >> _DRM_VBLANK_HIGH_CRTC_SHIFT;
	else
		crtc = flags & _DRM_VBLANK_SECONDARY ? 1 : 0;
1621
	if (crtc >= dev->num_crtcs)
1622 1623
		return -EINVAL;

1624 1625
	vblank = &dev->vblank[crtc];

1626 1627
	ret = drm_vblank_get(dev, crtc);
	if (ret) {
1628
		DRM_DEBUG("failed to acquire vblank counter, %d\n", ret);
1629 1630 1631
		return ret;
	}
	seq = drm_vblank_count(dev, crtc);
1632

1633
	switch (vblwait->request.type & _DRM_VBLANK_TYPES_MASK) {
L
Linus Torvalds 已提交
1634
	case _DRM_VBLANK_RELATIVE:
1635 1636
		vblwait->request.sequence += seq;
		vblwait->request.type &= ~_DRM_VBLANK_RELATIVE;
L
Linus Torvalds 已提交
1637 1638 1639
	case _DRM_VBLANK_ABSOLUTE:
		break;
	default:
1640 1641
		ret = -EINVAL;
		goto done;
L
Linus Torvalds 已提交
1642 1643
	}

1644 1645 1646 1647
	if (flags & _DRM_VBLANK_EVENT) {
		/* must hold on to the vblank ref until the event fires
		 * drm_vblank_put will be called asynchronously
		 */
1648
		return drm_queue_vblank_event(dev, crtc, vblwait, file_priv);
1649
	}
1650

1651
	if ((flags & _DRM_VBLANK_NEXTONMISS) &&
1652 1653
	    (seq - vblwait->request.sequence) <= (1<<23)) {
		vblwait->request.sequence = seq + 1;
1654 1655
	}

1656 1657
	DRM_DEBUG("waiting on vblank count %d, crtc %d\n",
		  vblwait->request.sequence, crtc);
1658 1659
	vblank->last_wait = vblwait->request.sequence;
	DRM_WAIT_ON(ret, vblank->queue, 3 * HZ,
1660 1661
		    (((drm_vblank_count(dev, crtc) -
		       vblwait->request.sequence) <= (1 << 23)) ||
1662
		     !vblank->enabled ||
1663
		     !dev->irq_enabled));
L
Linus Torvalds 已提交
1664

1665 1666
	if (ret != -EINTR) {
		struct timeval now;
L
Linus Torvalds 已提交
1667

1668
		vblwait->reply.sequence = drm_vblank_count_and_time(dev, crtc, &now);
1669 1670
		vblwait->reply.tval_sec = now.tv_sec;
		vblwait->reply.tval_usec = now.tv_usec;
1671

1672 1673
		DRM_DEBUG("returning %d to client\n",
			  vblwait->reply.sequence);
L
Linus Torvalds 已提交
1674
	} else {
1675
		DRM_DEBUG("vblank wait interrupted by signal\n");
L
Linus Torvalds 已提交
1676 1677
	}

1678 1679
done:
	drm_vblank_put(dev, crtc);
L
Linus Torvalds 已提交
1680 1681 1682
	return ret;
}

1683
static void drm_handle_vblank_events(struct drm_device *dev, int crtc)
1684 1685 1686 1687 1688
{
	struct drm_pending_vblank_event *e, *t;
	struct timeval now;
	unsigned int seq;

1689
	assert_spin_locked(&dev->event_lock);
1690

1691
	seq = drm_vblank_count_and_time(dev, crtc, &now);
1692 1693 1694 1695 1696 1697 1698 1699 1700 1701

	list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
		if (e->pipe != crtc)
			continue;
		if ((seq - e->event.sequence) > (1<<23))
			continue;

		DRM_DEBUG("vblank event on %d, current %d\n",
			  e->event.sequence, seq);

1702
		list_del(&e->base.link);
1703
		drm_vblank_put(dev, e->pipe);
1704
		send_vblank_event(dev, e, seq, &now);
1705 1706
	}

J
Jesse Barnes 已提交
1707
	trace_drm_vblank_event(crtc, seq);
1708 1709
}

1710 1711 1712 1713 1714 1715 1716
/**
 * drm_handle_vblank - handle a vblank event
 * @dev: DRM device
 * @crtc: where this event occurred
 *
 * Drivers should call this routine in their vblank interrupt handlers to
 * update the vblank counter and send any signals that may be pending.
1717 1718
 *
 * This is the legacy version of drm_crtc_handle_vblank().
1719
 */
1720
bool drm_handle_vblank(struct drm_device *dev, int crtc)
1721
{
1722
	struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
1723 1724 1725 1726 1727
	u32 vblcount;
	s64 diff_ns;
	struct timeval tvblank;
	unsigned long irqflags;

1728
	if (WARN_ON_ONCE(!dev->num_crtcs))
1729
		return false;
1730

R
Rob Clark 已提交
1731 1732 1733
	if (WARN_ON(crtc >= dev->num_crtcs))
		return false;

1734 1735
	spin_lock_irqsave(&dev->event_lock, irqflags);

1736 1737 1738 1739
	/* Need timestamp lock to prevent concurrent execution with
	 * vblank enable/disable, as this would cause inconsistent
	 * or corrupted timestamps and vblank counts.
	 */
1740
	spin_lock(&dev->vblank_time_lock);
1741 1742

	/* Vblank irq handling disabled. Nothing to do. */
1743
	if (!vblank->enabled) {
1744 1745
		spin_unlock(&dev->vblank_time_lock);
		spin_unlock_irqrestore(&dev->event_lock, irqflags);
1746
		return false;
1747 1748 1749 1750 1751 1752 1753
	}

	/* Fetch corresponding timestamp for this vblank interval from
	 * driver and store it in proper slot of timestamp ringbuffer.
	 */

	/* Get current timestamp and count. */
1754
	vblcount = vblank->count;
1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769
	drm_get_last_vbltimestamp(dev, crtc, &tvblank, DRM_CALLED_FROM_VBLIRQ);

	/* Compute time difference to timestamp of last vblank */
	diff_ns = timeval_to_ns(&tvblank) -
		  timeval_to_ns(&vblanktimestamp(dev, crtc, vblcount));

	/* Update vblank timestamp and count if at least
	 * DRM_REDUNDANT_VBLIRQ_THRESH_NS nanoseconds
	 * difference between last stored timestamp and current
	 * timestamp. A smaller difference means basically
	 * identical timestamps. Happens if this vblank has
	 * been already processed and this is a redundant call,
	 * e.g., due to spurious vblank interrupts. We need to
	 * ignore those for accounting.
	 */
1770 1771 1772
	if (abs64(diff_ns) > DRM_REDUNDANT_VBLIRQ_THRESH_NS)
		store_vblank(dev, crtc, 1, &tvblank);
	else
1773 1774 1775
		DRM_DEBUG("crtc %d: Redundant vblirq ignored. diff_ns = %d\n",
			  crtc, (int) diff_ns);

1776 1777
	spin_unlock(&dev->vblank_time_lock);

1778
	wake_up(&vblank->queue);
1779
	drm_handle_vblank_events(dev, crtc);
1780

1781 1782
	spin_unlock_irqrestore(&dev->event_lock, irqflags);

1783
	return true;
1784 1785
}
EXPORT_SYMBOL(drm_handle_vblank);
1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803

/**
 * drm_crtc_handle_vblank - handle a vblank event
 * @crtc: where this event occurred
 *
 * Drivers should call this routine in their vblank interrupt handlers to
 * update the vblank counter and send any signals that may be pending.
 *
 * This is the native KMS version of drm_handle_vblank().
 *
 * Returns:
 * True if the event was successfully handled, false on failure.
 */
bool drm_crtc_handle_vblank(struct drm_crtc *crtc)
{
	return drm_handle_vblank(crtc->dev, drm_crtc_index(crtc));
}
EXPORT_SYMBOL(drm_crtc_handle_vblank);