We're currently miscalculating the line and pixel durations for
interlaced modes. crtc_htotal and crtc_vtotal are the full frame
timings, and so is crtc_clock, so we can compute the line
and pixel durations from those w/o any extra adjustments. But
we actually want framedur_ns to be the field, not frame, duration,
so we must divide it by two.

This should make the scanout based vblank timestamp corrections
work correctly with interlaced modes, at least for i915. It all
depends whether we keep the field or frame timings in the display
mode crtc_ timings.

v2: Preserve halve->half typo fix that happened in the meantine

Reviewed-by: mario.kleiner.de@gmail.com
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>

Using s64 for the timestamping constants is wasteful. Signed 32bit
integers get us a range of over +-2 seconds. Presuming that no-one
wants to a vrefresh rate less than 0.5, we can switch to using int
for the timestamping constants. We save a few bytes in drm_crtc and
avoid a bunch of 64bit math.

Reviewed-by: mario.kleiner.de@gmail.com
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>

drm_calc_timestamping_constants() computes the pixel/line/frame
durations based on the crtc_ timing values. The corresponding pixel
clock is in mode->crtc_clock, so we need to use that instead of
mode->clock.

This should fix drm_calc_timestamping_constants() for frame packing
stereo modes.

Reviewed-by: mario.kleiner.de@gmail.com
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>

drm_calc_timestamping_constants() makes the math more complex
than necessary.
- multipying the dotclock by 1000 is pointless, just makes all the
  numbers bigger
- div64_u64() is also pointless, div_u64 is enough
- pixeldur_ns doesn't need any 64bit math

Reviewed-by: mario.kleiner.de@gmail.com
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>

Move the long blurp to into the body of the comment, leaving only
a short summary line at the top.

Reviewed-by: mario.kleiner.de@gmail.com
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>

Rather than using crtc->hwmode, just pass the relevant mode to
drm_calc_vbltimestamp_from_scanoutpos(). This removes the last hwmode
usage from core drm.

Reviewed-by: mario.kleiner.de@gmail.com
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>

We don't really use hwmode anymore in i915, so eliminating its use
from the core code seems prudent. Just pass the appropriate mode
to drm_calc_timestamping_constants().

Reviewed-by: mario.kleiner.de@gmail.com
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>

Less yelling ftw!
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NDave Airlie <airlied@redhat.com>

We don't have any userspace interfaces that use HZ as a time unit, so
having our own DRM define is useless.

Remove this remnant from the shared drm core days.
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NDave Airlie <airlied@redhat.com>

A change in locking of some kms drivers (currently intel-kms) make
the old approach too inaccurate and also incompatible with the
PREEMPT_RT realtime kernel patchset.

The driver->get_scanout_position() method of intel-kms now needs
to aquire a spinlock, which clashes badly with the former
preempt_disable() calls in the drm, and it also introduces larger
delays and timing uncertainty on a contended lock than acceptable.

This patch changes the prototype of driver->get_scanout_position()
to require/allow kms drivers to perform the ktime_get() system time
queries which go along with actual scanout position readout in a way
that provides maximum precision and to return those timestamps to
the drm. kms drivers implementations of get_scanout_position() are
asked to implement timestamping and scanoutpos readout in a way
that is as precise as possible and compatible with preempt_disable()
on a PREMPT_RT kernel. A driver should follow this pattern in
get_scanout_position() for precision and compatibility:

spin_lock...(...);
preempt_disable_rt(); // On a PREEMPT_RT kernel, otherwise omit.
if (stime) *stime = ktime_get();
... Minimum amount of MMIO register reads to get scanout position ...
... no taking of locks allowed here! ...
if (etime) *etime = ktime_get();
preempt_enable_rt(); // On PREEMPT_RT kernel, otherwise omit.
spin_unlock...(...);

v2: Fix formatting of new multi-line code comments.
Signed-off-by: NMario Kleiner <mario.kleiner.de@gmail.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Preemption handling will get pushed into the kms
drivers in followup patches, to make timestamping
more robust and PREEMPT_RT friendly.
Signed-off-by: NMario Kleiner <mario.kleiner.de@gmail.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Signed-off-by: NMichael Witten <mfwitten@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

irq_enabled is only ever 0 or 1, so make it a bool.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

drm_vblank_init() is too ugly. Make it a bit easier on the eye by
collecting all the per-crtc vblank counters, timestamps etc. to
a structure and just allocate an array of those.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

vblank_enabled is only ever 0 or 1, so make it a bool.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

vblank_disable_allowed is only ever 0 or 1, so make it a bool.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

It takes an unsigned value. This happens not to blow up on 64-bit
architectures, but it does on 32-bit, causing
drm_calc_vbltimestamp_from_scanoutpos() to calculate totally bogus
timestamps for vblank events. Which in turn causes e.g. gnome-shell to
hang after a DPMS off cycle with current xf86-video-ati Git.

[airlied: regression introduced in drm: use monotonic time in drm_calc_vbltimestamp_from_scanoutpos]

Cc: stable@vger.kernel.org
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=59339
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=59836Tested-by: Nshui yangwei <yangweix.shui@intel.com>
Signed-off-by: NMichel Dänzer <michel.daenzer@amd.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

When GPU acceleration is disabled, drm_vblank_cleanup() will free the
vblank-related data, such as vblank_refcount, vblank_inmodeset, etc.
But we found that drm_vblank_post_modeset() may be called after the
cleanup, which use vblank_refcount and vblank_inmodeset. And this will
cause a kernel panic.

Fix this by return immediately if dev->num_crtcs is zero. This is the
same thing that drm_vblank_pre_modeset() does.

Call trace of a drm_vblank_post_modeset() after drm_vblank_cleanup():
[   62.628906] [<ffffffff804868d0>] drm_vblank_post_modeset+0x34/0xb4
[   62.628906] [<ffffffff804c7008>] atombios_crtc_dpms+0xb4/0x174
[   62.628906] [<ffffffff804c70e0>] atombios_crtc_commit+0x18/0x38
[   62.628906] [<ffffffff8047f038>] drm_crtc_helper_set_mode+0x304/0x3cc
[   62.628906] [<ffffffff8047f92c>] drm_crtc_helper_set_config+0x6d8/0x988
[   62.628906] [<ffffffff8047dd40>] drm_fb_helper_set_par+0x94/0x104
[   62.628906] [<ffffffff80439d14>] fbcon_init+0x424/0x57c
[   62.628906] [<ffffffff8046a638>] visual_init+0xb8/0x118
[   62.628906] [<ffffffff8046b9f8>] take_over_console+0x238/0x384
[   62.628906] [<ffffffff80436df8>] fbcon_takeover+0x7c/0xdc
[   62.628906] [<ffffffff8024fa20>] notifier_call_chain+0x44/0x94
[   62.628906] [<ffffffff8024fcbc>] __blocking_notifier_call_chain+0x48/0x68
[   62.628906] [<ffffffff8042d990>] register_framebuffer+0x228/0x260
[   62.628906] [<ffffffff8047e010>] drm_fb_helper_single_fb_probe+0x260/0x314
[   62.628906] [<ffffffff8047e2c4>] drm_fb_helper_initial_config+0x200/0x234
[   62.628906] [<ffffffff804e5560>] radeon_fbdev_init+0xd4/0xf4
[   62.628906] [<ffffffff804e0e08>] radeon_modeset_init+0x9bc/0xa18
[   62.628906] [<ffffffff804bfc14>] radeon_driver_load_kms+0xdc/0x12c
[   62.628906] [<ffffffff8048b548>] drm_get_pci_dev+0x148/0x238
[   62.628906] [<ffffffff80423564>] local_pci_probe+0x5c/0xd0
[   62.628906] [<ffffffff80241ac4>] work_for_cpu_fn+0x1c/0x30
[   62.628906] [<ffffffff802427c8>] process_one_work+0x274/0x3bc
[   62.628906] [<ffffffff80242934>] process_scheduled_works+0x24/0x44
[   62.628906] [<ffffffff8024515c>] worker_thread+0x31c/0x3f4
[   62.628906] [<ffffffff802497a8>] kthread+0x88/0x90
[   62.628906] [<ffffffff80206794>] kernel_thread_helper+0x10/0x18
Signed-off-by: NHuacai Chen <chenhc@lemote.com>
Signed-off-by: NBinbin Zhou <zhoubb@lemote.com>
Cc: <stable@vger.kernel.org>
Reviewed-by: NMichel Dänzer <michel.daenzer@amd.com>
Acked-by: NPaul Menzel <paulepanter@users.sourceforge.net>
Signed-off-by: NDave Airlie <airlied@gmail.com>

Initialize e->pipe.. some drivers set this themselves, others do not.
Setting it in drm_send_vblank_event() should help ensure more consistent
behavior with the different drivers.
Signed-off-by: NRob Clark <robdclark@gmail.com>

It is a bit more precise to compute the total number of pixels first and
then divide, rather than multiplying the line pixel count by the
already-rounded line duration.
Signed-off-by: NDaniel Kurtz <djkurtz@chromium.org>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Drivers that register interrupt handlers without the DRM core helpers
don't initialize the .irq_enabled field and drm_dev_to_irq() may fail
when called on them. This shouldn't preclude them from implementing
the vblank IOCTL.
Signed-off-by: NThierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Currently the only users of drm_vblank_off() are i915 and gma500,
neither of which holds the event_lock when calling this function.
Fix this by holding the event_lock while traversing the list.
Signed-off-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NInki Dae <inki.dae@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>

When trying to obtain an accurate timestamp for the last vsync interrupt
in vblank_disable_and_save() we loop until the vsync counter after reading
the time stamp is identical to the one before.
In the case where no hardware timestamp can be obtained there is probably
no point in trying to make sure we remain within the same vsync during
the time we obtain the counter.
Furthermore we should make sure there's an 'emergency exit' so that we
don't end up in an endless loop when the driver get_vblank_timestamp()
function doesn't manage to return within the same vsync.
This may happen when this function prints out debugging information over
a slow (ie serial) line.
Signed-off-by: NEgbert Eich <eich@suse.de>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Jumps in the vblank and page flip event timestamps cause trouble for
clients, so we should avoid them. The timestamp we get currently with
gettimeofday can jump, so use instead monotonic timestamps.

For backward compatibility use a module flag to revert back to using
gettimeofday timestamps. Add also a DRM_CAP_TIMESTAMP_MONOTONIC flag
that is simply a read only version of the module flag, so that clients
can query this without depending on sysfs.
Signed-off-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

For measuring duration we want to avoid that our start/end timestamps
jump, so use monotonic instead of real time for that.
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: mario.kleiner
Signed-off-by: NDave Airlie <airlied@redhat.com>

A helper that drivers can use to send vblank event after a pageflip.
If the driver doesn't support proper vblank irq based time/seqn then
just pass -1 for the pipe # to get do_gettimestamp() behavior (since
there are a lot of drivers that don't use drm_vblank_count_and_time())

Also an internal send_vblank_event() helper for the various other code
paths within drm_irq that also need to send vblank events.

v1: original
v2: add back 'vblwait->reply.sequence = seq' which should not have
    been deleted
v3: add WARN_ON() in case lock is not held and comments
v4: use WARN_ON_SMP() instead to fix issue with !SMP && !DEBUG_SPINLOCK
    as pointed out by Marcin Slusarz
v5: update docbook
Signed-off-by: NRob Clark <rob@ti.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Convert #include "..." to #include <path/...> in drivers/gpu/.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Acked-by: NDave Airlie <airlied@redhat.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: NDave Jones <davej@redhat.com>

Fixes the following sparse warning:
drivers/gpu/drm/drm_irq.c:1239:6:
warning: symbol 'drm_handle_vblank_events' was not declared. Should it be static?
Signed-off-by: NSachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: NDave Airlie <airlied@redhat.com>

DRM_IOCTL_MODESET_CTL must only be used for UMS drivers. Make it a no-op
for KMS drivers.
Signed-off-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: NMichel Dänzer <michel@daenzer.net>
Signed-off-by: NDave Airlie <airlied@gmail.com>

Signed-off-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

A race condition exists in drm_vblank_cleanup() if the vblank disable
timer callback runs after freeing the memory that its callback function
tries to access. Fix this by deleting the timer synchronously.
Signed-off-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

remove declared but unused functions from drmP.h, fix the comments
where necessary. Also, remove drm_mem_info which is unused.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NDave Airlie <airlied@redhat.com>

commit 27641c3f (drm/vblank: Add support for precise vblank
timestamping) adds preempt_disable()/enable() around a spin locked
section with the comments:

 * Disable preemption, so vblank_time_lock is held as short as
 * possible, even under a kernel with PREEMPT_RT patches.

/* Disable preemption while holding vblank_time_lock. Do
 * it explicitely to guard against PREEMPT_RT kernel.

Just that this has never been tested on a RT kernel which would have
granted that nonsense with a might_sleep() warning because
dev->vblank_time_lock is converted to a "sleeping" spinlock on RT.

So this is activly wrong on RT and superflous on mainline. Remove it.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NMario Kleiner <mario.kleiner@tuebingen.mpg.de>
Signed-off-by: NDave Airlie <airlied@redhat.com>

during the review of the fix for locks problems in drm_wait_vblank,
a couple of false concerns were raised about how the drm_vblank_get
and drm_vblank_put are used in this function; it turned out that the
code is correct and that it cannot be simplified

add a few comments to explain non-obvious flows in the code,
to prevent "false alarms" in the future

v2: incorporate comments received from Daniel Vetter
Signed-off-by: NIlija Hadzic <ihadzic@research.bell-labs.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Signed-off-by: NBen Skeggs <bskeggs@redhat.com>

They need this to get all the EXPORT_SYMBOL variants and THIS_MODULE
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

The struct drm_driver has some function pointers for irq. They are
gpu specific and some functions aren't essential things. This can
prevents creation of unnecessary dummy function for irq.
Signed-off-by: NJoonyoung Shim <jy0922.shim@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

The registered irq should be unregistered by free_irq() if
irq_postinstall() returns the error after request_irq() is called
successfully.

[airlied: add vga switcheroo disable]
Signed-off-by: NJoonyoung Shim <jy0922.shim@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

This is the least-bad behaviour.  It means that we signal the
vblank event before it actually happens, but since we're disabling
vblanks there's no guarantee that it will *ever* happen otherwise.

This prevents GL applications which use WaitMSC from hanging
indefinitely.
Signed-off-by: NChristopher James Halse Rogers <christopher.halse.rogers@canonical.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Add __attribute__((format (printf, 4, 5))) to drm_ut_debug_printk
and fix fallout.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>