drm_vblank_off() will turn off vblank interrupts, but as long as the
refcount is elevated drm_vblank_get() will not re-enable them. This
is a problem is someone is holding a vblank reference while a modeset is
happening, and the driver requires vblank interrupt to work during that
time.

Add drm_vblank_on() as a counterpart to drm_vblank_off() which will
re-enabled vblank interrupts if the refcount is already elevated. This
will allow drivers to choose the specific places in the modeset sequence
at which vblank interrupts get disabled and enabled.

Testcase: igt/kms_flip/*-vs-suspend
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
[danvet: Add Testcase tag for the igt I've written.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

If there's a blocking vblank wait in progress while the vblank interrupt
gets disabled, the current code will just let the vblank wait time out.
Instead make it return immediately when vblank interrupts get disabled.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Currently there's one per-device vblank disable timer, and it gets
reset wheneven the vblank refcount for any crtc drops to zero. That
means that one crtc could accidentally be keeping the vblank interrupts
for other crtcs enabled even if there are no users for them. Make the
disable timer per-crtc to avoid this issue.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The irq flags state is already established by the outer
spin_lock_irqsave(); re-disabling irqs is redundant.
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This was only ever used to pretty-print the irq driver name. And on
kms systems due to set_version bonghits we never set up the prettier
name, ever. Which make this a bit pointless.

Also, we can always dig out the driver-instance/irq relationship
through other means, so this isn't that useful. So just rip it out to
simplify the set_version/set_busid insanity a bit.

Also delete the temporary busname from drm_pci_set_busid, it's now
unused.

v2: Rebase on top of the new host1x drm_bus for tegra.
Reviewed-by: NThierry Reding <treding@nvidia.com>
Reviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Unfortunately this requires a drm-wide change, and I didn't see a sane
way around that. Luckily it's fairly simple, we just need to inline
the respective get_irq implementation from either drm_pci.c or
drm_platform.c.

With that we can now also remove drm_dev_to_irq from drm_irq.c.
Reviewed-by: NThierry Reding <treding@nvidia.com>
Reviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

It's only ever called for legacy drivers, which are all pci.
Reviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

To get rid of the dev->bus->get_irq callback we need to pass in the
desired irq explicitly into drm_irq_install. To avoid having to do the
same for drm_irq_unistall just track it internally. That leaves
drivers with less room to botch things up.

v2: Add the hunk lost in an earlier patch to this one (Thierry).

v3: Fix up the totally fumbled logic in drm_irq_install and use the
local variable consistently. Spotted by both Thierry and Laurent.
Shame on me for failing to properly test the rebase version of this
patch ...

Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Only used in some legacy pci drivers, and dereferencing the PCI irq is
actually shorter ...

Since this removes all users for drm_dev_to_irq from the tree except
in drm_irq.c, move the inline helper in there. It'll disappear soon,
too.

v2: Polish commit message (Thierry)
Reviewed-by: NThierry Reding <treding@nvidia.com>
Reviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The dev->struct_mutex locking in drm_irq.c only protects
dev->irq_enabled. Which isn't really much at all and only prevents
especially nasty ums userspace from concurrently installing the
interrupt handling a few times. Or at least trying.

There are tons of unlocked readers of dev->irqs_enabled in the vblank
wait code (and by extension also in the pageflip code since that uses
the same vblank timestamp engine).

Real modesetting drivers should ensure that nothing can go haywire
with a sane setup teardown sequence. So we only really need this for
the drm_control ioctl, everywhere else this will just paper over
nastiness.

Note that drm/i915 is a bit specially due to the gem+ums combination.
So there we also need to properly protect the entervt and leavevt
ioctls. But it's definitely saner to do everything in one go than to
drop the lock in-between.

Finally there's the gpu reset code in drm/i915. That one's just race
(concurrent userspace calls to for vblank waits of pageflips could
spuriously fail). So wrap it up in with a nice comment since fixing
this is more involved.

v2: Rebase and fix commit message (Thierry)
Reviewed-by: NThierry Reding <treding@nvidia.com>
Reviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This just adds a correspdonding check, follow-up patches will exploit
this.

v2: Whitespace polish (Thierry)
Reviewed-by: NThierry Reding <treding@nvidia.com>
Reviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This is a ums-only ioctl, and we've only ever supported ums (at least
in upstream) on pci devices. So no point in keeping that piece of
legacy logic abstracted within the drm bus driver.

To keep things work without CONFIG_PCI also add a dummy ioctl.

v2: Block the irq_by_busid ioctl for modeset drivers.

v3: Spelling/whitespace polish (Thierry)
Reviewed-by: NThierry Reding <treding@nvidia.com>
Reviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Checking for both an irq number _and_ whether it's enabled is
redundant. Originally I've thought the drm_dev_to_irq call would break
drivers which do their own irq checking, but those shouldn't have
DRIVER_HAVE_IRQ set as Thierry Reding pointed out. But such drivers
already need to set dev->irq_enabled for other reasons, so we might as
well ditch that check, too.

v2: Also drop the HAVE_IRQ check.

Cc: Thierry Reding <thierry.reding@gmail.com>
Reviewed-by: NThierry Reding <treding@nvidia.com>
Reviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

i915 doesn't need this kludge for most platforms. Although we do
appear to need something similar on certain platforms, but we can
be more accurate when we apply the adjustment since we know exactly
why the scanline counter doesn't always quite match the vblank
status.

Also the current code doesn't handle interlaced modes correctly,
and we already deal with interlaced modes in i915 code.

So let's just move the current code to radeon_get_crtc_scanoutpos()
since that's why it was added. For i915 we'll add a more finely
targeted variant.

v2: Fix vpos vs. *vpos bug (Mario)

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

Preparation for moving the early vblank IRQ logic into
radeon_get_crtc_scanoutpos().

v2: Fix radeon_drv.c compile warning (Mario)

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

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>