drm/vblank: Add helper to get next vblank time

Will be used in the next commit to set a deadline on fences that an
atomic update is waiting on.

v2: Calculate time at *start* of vblank period, not end
v3: Fix kbuild complaints

Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Mario Kleiner <mario.kleiner.de@gmail.com>

drm/vblank: Document drm_crtc_vblank_restore constraints

I got real badly confused when trying to review a fix from Ville for
this. Let's try to document better what's required for this, and check
the minimal settings at runtime - we can't check ofc that there's
indeed no races in the driver callback.

Also noticed that the drm_vblank_restore version is unused, so lets
unexport that while at it.

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210209101523.2954281-1-daniel.vetter@ffwll.ch

drm/vblank: Add vblank works

Add some kind of vblank workers. The interface is similar to regular
delayed works, and is mostly based off kthread_work. It allows for
scheduling delayed works that execute once a particular vblank sequence
has passed. It also allows for accurate flushing of scheduled vblank
works - in that flushing waits for both the vblank sequence and job
execution to complete, or for the work to get cancelled - whichever
comes first.

Whatever hardware programming we do in the work must be fast (must at
least complete during the vblank or scanout period, sometimes during the
first few scanlines of the vblank). As such we use a high-priority
per-CRTC thread to accomplish this.

Changes since v7:
* Stuff drm_vblank_internal.h and drm_vblank_work_internal.h contents
into drm_internal.h
* Get rid of unnecessary spinlock in drm_crtc_vblank_on()
* Remove !vblank->worker check
* Grab vbl_lock in drm_vblank_work_schedule()
* Mention self-rearming work items in drm_vblank_work_schedule() kdocs
* Return 1 from drm_vblank_work_schedule() if the work was scheduled
successfully, 0 or error code otherwise
* Use drm_dbg_core() instead of DRM_DEV_ERROR() in
drm_vblank_work_schedule()
* Remove vblank->worker checks in drm_vblank_destroy_worker() and
drm_vblank_flush_worker()
Changes since v6:
* Get rid of ->pending and seqcounts, and implement flushing through
simpler means - danvet
* Get rid of work_lock, just use drm_device->event_lock
* Move drm_vblank_work item cleanup into drm_crtc_vblank_off() so that
we ensure that all vblank work has finished before disabling vblanks
* Add checks into drm_crtc_vblank_reset() so we yell if it gets called
while there's vblank workers active
* Grab event_lock in both drm_crtc_vblank_on()/drm_crtc_vblank_off(),
the main reason for this is so that other threads calling
drm_vblank_work_schedule() are blocked from attempting to schedule
while we're in the middle of enabling/disabling vblanks.
* Move drm_handle_vblank_works() call below drm_handle_vblank_events()
* Simplify drm_vblank_work_cancel_sync()
* Fix drm_vblank_work_cancel_sync() documentation
* Move wake_up_all() calls out of spinlock where we can. The only one I
left was the call to wake_up_all() in drm_vblank_handle_works() as
this seemed like it made more sense just living in that function
(which is all technically under lock)
* Move drm_vblank_work related functions into their own source files
* Add drm_vblank_internal.h so we can export some functions we don't
want drivers using, but that we do need to use in drm_vblank_work.c
* Add a bunch of documentation
Changes since v4:
* Get rid of kthread interfaces we tried adding and move all of the
locking into drm_vblank.c. For implementing drm_vblank_work_flush(),
we now use a wait_queue and sequence counters in order to
differentiate between multiple work item executions.
* Get rid of drm_vblank_work_cancel() - this would have been pretty
difficult to actually reimplement and it occurred to me that neither
nouveau or i915 are even planning to use this function. Since there's
also no async cancel function for most of the work interfaces in the
kernel, it seems a bit unnecessary anyway.
* Get rid of to_drm_vblank_work() since we now are also able to just
pass the struct drm_vblank_work to work item callbacks anyway
Changes since v3:
* Use our own spinlocks, don't integrate so tightly with kthread_works
Changes since v2:
* Use kthread_workers instead of reinventing the wheel.

Cc: Tejun Heo <tj@kernel.org>
Cc: dri-devel@lists.freedesktop.org
Cc: nouveau@lists.freedesktop.org
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Co-developed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Lyude Paul <lyude@redhat.com>
Acked-by: Dave Airlie <airlied@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200627194657.156514-4-lyude@redhat.com

drm: Remove legacy version of get_scanout_position()

The legacy version of get_scanout_position() was only useful while
drivers still used drm_driver.get_scanout_position(). With no such
drivers left, the related typedef and code can be removed

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200123135943.24140-23-tzimmermann@suse.de

drm: Clean-up VBLANK-related callbacks in struct drm_driver

All non-legacy users of VBLANK functions in struct drm_driver have been
converted to use the respective interfaces in struct drm_crtc_funcs. The
remaining users of VBLANK callbacks in struct drm_driver are legacy drivers
with userspace modesetting.

All users of struct drm_driver.get_scanout_position() have been
converted to the respective CRTC helper function. Remove the callback
from struct drm_driver.

There are no users left of get_vblank_timestamp(), so the callback is
being removed. The other VBLANK callbacks are being moved to the legacy
section at the end of struct drm_driver.

Also removed is drm_calc_vbltimestamp_from_scanoutpos(). Callers of this
function have been converted to use the CRTC instead.

v4:
* more readable code for setting high_prec (Ville, Jani)
v2:
* merge with removal of struct drm_driver.get_scanout_position()
* remove drm_calc_vbltimestamp_from_scanoutpos()

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Tested-by: Yannick Fertré <yannick.fertre@st.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200123135943.24140-22-tzimmermann@suse.de

drm: Add get_vblank_timestamp() to struct drm_crtc_funcs

The callback get_vblank_timestamp() is currently located in struct
drm_driver, but really belongs into struct drm_crtc_funcs. Add an
equivalent there. Driver will be converted in separate patches.

The default implementation is drm_calc_vbltimestamp_from_scanoutpos().
The patch adds drm_crtc_vblank_helper_get_vblank_timestamp(), which is
an implementation for the CRTC callback.

v4:
* more readable code for setting high_prec (Ville, Jani)
v3:
* use refactored timestamp calculation to minimize duplicated code
* do more checks for crtc != NULL to support legacy drivers
v2:
* rename helper to drm_crtc_vblank_helper_get_vblank_timestamp()
* replace drm_calc_vbltimestamp_from_scanoutpos() with
drm_crtc_vblank_helper_get_vblank_timestamp() in docs

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200123135943.24140-4-tzimmermann@suse.de

drm: Add get_scanout_position() to struct drm_crtc_helper_funcs

The new callback get_scanout_position() reads the current location
of the scanout process. The operation is currently located in struct
drm_driver, but really belongs to the CRTC. Drivers will be converted
in separate patches.

To help with the conversion, the timestamp calculation has been
moved from drm_calc_vbltimestamp_from_scanoutpos() to
drm_crtc_vblank_helper_get_vblank_timestamp_internal(). The helper
function supports the new and old interface of get_scanout_position().
drm_calc_vbltimestamp_from_scanoutpos() remains as a wrapper around
the new function.

Callback functions return the scanout position from the CRTC. The
legacy version of the interface receives the device and pipe index,
the modern version receives a pointer to the CRTC. We keep the
legacy version until all drivers have been converted.

v4:
* 80-character line fixes
v3:
* refactor drm_calc_vbltimestamp_from_scanoutpos() to minimize
code duplication
* define types for get_scanout_position() callbacks
v2:
* fix logical op in drm_calc_vbltimestamp_from_scanoutpos()

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Tested-by: Yannick Fertré <yannick.fertre@st.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200123135943.24140-3-tzimmermann@suse.de

drm: Initialize struct drm_crtc_state.no_vblank from device settings

At the end of a commit, atomic helpers can generate a fake VBLANK event
automatically. Originally implemented for writeback connectors, the
functionality can be used by any driver and/or hardware without proper
VBLANK interrupt.

The patch updates the documentation to make this behaviour official:
settings struct drm_crtc_state.no_vblank to true enables automatic
generation of fake VBLANK events.

The new interface drm_dev_has_vblank() returns true if vblanking has
been initialized for a device, or false otherwise. Atomic helpers use
this function when initializing no_vblank in the CRTC state in
drm_atomic_helper_check_modeset(). If vblanking has been initialized
for a device, no_blank is disabled. Otherwise it's enabled. Hence,
atomic helpers will automatically send out fake VBLANK events with any
driver that did not initialize vblanking.

v5:
* more precise documentation and commit message
v4:
* replace drm_crtc_has_vblank() with drm_dev_has_vblank()
* add drm_dev_has_vblank() in this patch
* move driver changes into separate patches
v3:
* squash all related changes patches into this patch

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200129120531.6891-2-tzimmermann@suse.de

drm/vblank: Document and fix vblank count barrier semantics

Noticed while reviewing code. I'm not sure whether this might or might
not explain some of the missed vblank hilarity we've been seeing on
various drivers (but those got tracked down to driver issues, at least
mostly). I think those all go through the vblank completion event,
which has unconditional barriers - it always takes the spinlock.
Therefore no cc stable.

v2:
- Barrriers are hard, put them in in the right order (Chris).
- Improve the comments a bit.

v3:

Ville noticed that on 32bit we might be breaking up the load/stores,
now that the vblank counter has been switched over to be 64 bit. Fix
that up by switching to atomic64_t. This this happens so rarely in
practice I figured no need to cc: stable ...

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Keith Packard <keithp@keithp.com>
References: 570e86963a51 ("drm: Widen vblank count to 64-bits [v3]")
Cc: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190723131337.22031-1-daniel.vetter@ffwll.ch

drm: drop uapi dependency from drm_vblank.h

drm_vblank.h included uapi/drm/drm.h.
It turns out this include was not required - delete it.

Note: uapi/drm/drm.h is included indirect via drm_file.h,
but there are no dependencies in drm_vblank.h so the removal
is legit.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Sean Paul <sean@poorly.run>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <maxime.ripard@bootlin.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Stefan Agner <stefan@agner.ch>
Cc: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190718161507.2047-4-sam@ravnborg.org

drm/vblank: Allow dynamic per-crtc max_vblank_count

On i965gm we need to adjust max_vblank_count dynamically
depending on whether the TV encoder is used or not. To
that end add a per-crtc max_vblank_count that takes
precedence over its device wide counterpart. The driver
can now call drm_crtc_set_max_vblank_count() to configure
the per-crtc value before calling drm_vblank_on().

Also looks like there was some discussion about exynos needing
similar treatment.

v2: Drop the extra max_vblank_count!=0 check for the
WARN(last!=current), will take care of it in i915 code (Daniel)
WARN_ON(!inmodeset) (Daniel)
WARN_ON(dev->max_vblank_count)
Pimp up the docs (Daniel)

Cc: stable@vger.kernel.org
Cc: Inki Dae <inki.dae@samsung.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181127182004.28885-1-ville.syrjala@linux.intel.com
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drm/vblank: Remove old-style comments

Somehow I forgot a few when typing all the shiny new kerneldoc. Drop
them.

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181005073636.27291-1-daniel.vetter@ffwll.ch

drm/doc: Use new substruct support

Support for this just recently landed in linux-next.

Reviewed-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180219225356.24996-5-daniel.vetter@ffwll.ch

drm/vblank: Restoring vblank counts after device PM events.

The HW frame counter can get reset if device enters a low power state after
vblank interrupts were disabled. This messes up any following vblank count
update as a negative diff (huge unsigned diff) is calculated from the HW
frame counter change. We cannot ignore negative diffs altogther as there
could be legitimate wrap arounds. So, allow drivers to update vblank->count
with missed vblanks for the time interrupts were disabled. This is similar
to _crtc_vblank_on() except that vblanks interrupts are not enabled at the
end as this function is expected to be called from the driver
_enable_vblank() vfunc.

v2: drm_crtc_vblank_restore should take crtc as arg. (Chris)
Add docs and sprinkle some asserts.

Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Michel Dänzer <michel@daenzer.net>
Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180203051302.9974-9-dhinakaran.pandiyan@intel.com

drm/vblank: Data type fixes for 64-bit vblank sequences.

drm_vblank_count() has an u32 type returning what is a 64-bit vblank count.
The effect of this is when drm_wait_vblank_ioctl() tries to widen the user
space requested vblank sequence using this clipped 32-bit count(when the
value is >= 2^32) as reference, the requested sequence remains a 32-bit
value and gets queued like that. However, the code that checks if the
requested sequence has passed compares this against the 64-bit vblank
count.

With drm_vblank_count() returning all bits of the vblank count, update
drm_crtc_accurate_vblank_count() so that drm_crtc_arm_vblank_event() queues
the correct sequence. Otherwise, this leads to prolonged waits for a vblank
sequence when the current count is >=2^32.

Finally, fix drm_wait_one_vblank() too.

v2: Commit message fix (Keith)
Squash commits (Rodrigo)

Fixes: 570e86963a51 ("drm: Widen vblank count to 64-bits [v3]")
Cc: Keith Packard <keithp@keithp.com>
Cc: Michel Dänzer <michel@daenzer.net>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180203051302.9974-1-dhinakaran.pandiyan@intel.com

drm: Add CRTC_GET_SEQUENCE and CRTC_QUEUE_SEQUENCE ioctls [v3]

These provide crtc-id based functions instead of pipe-number, while
also offering higher resolution time (ns) and wider frame count (64)
as required by the Vulkan API.

v2:

* Check for DRIVER_MODESET in new crtc-based vblank ioctls

Failing to check this will oops the driver.

* Ensure vblank interupt is running in crtc_get_sequence ioctl

The sequence and timing values are not correct while the
interrupt is off, so make sure it's running before asking for
them.

* Short-circuit get_sequence if the counter is enabled and accurate

Steal the idea from the code in wait_vblank to avoid the
expense of drm_vblank_get/put

* Return active state of crtc in crtc_get_sequence ioctl

Might be useful for applications that aren't in charge of
modesetting?

* Use drm_crtc_vblank_get/put in new crtc-based vblank sequence ioctls

Daniel Vetter prefers these over the old drm_vblank_put/get
APIs.

* Return s64 ns instead of u64 in new sequence event

Suggested-by: Daniel Vetter <daniel@ffwll.ch>
Suggested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

v3:

* Removed FIRST_PIXEL_OUT_FLAG
* Document that the timestamp in the query and event are
that of the first pixel leaving the display engine for
the display (using the same wording as the Vulkan spec).

Suggested-by: Michel Dänzer <michel@daenzer.net>
Acked-by: Dave Airlie <airlied@redhat.com>

[airlied: left->leaves (Michel)]

Signed-off-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drm: Reorganize drm_pending_event to support future event types [v2]

Place drm_event_vblank in a new union that includes that and a bare
drm_event structure. This will allow new members of that union to be
added in the future without changing code related to the existing vbl
event type.

Assignments to the crtc_id field are now done when the event is
allocated, rather than when delievered. This way, delivery doesn't
need to have the crtc ID available.

v2:
* Remove 'dev' argument from create_vblank_event

It wasn't being used anyways, and if we need it in the future,
we can always get it from crtc->dev.

* Check for MODESETTING before looking for crtc in queue_vblank_event

UMS drivers will oops if we try to get a crtc, so make sure
we're modesetting before we try to find a crtc_id to fill into
the event.

Signed-off-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
(cherry picked from commit dc695b85fde88eca3ef3b03fcd82f15b6bc6e462)

drm: Widen vblank count to 64-bits [v3]

This modifies the datatypes used by the vblank code to provide 64 bits
of vblank count.

The driver interfaces have been left using 32 bits of vblank count;
all of the code necessary to widen that value for the user API was
already included to handle devices returning fewer than 32-bits.

This will provide the necessary datatypes for the Vulkan API.

v2:

* Re-write wait_vblank ioctl to ABSOLUTE sequence

When an application uses the WAIT_VBLANK ioctl with RELATIVE
or NEXTONMISS bits set, the target vblank interval is updated
within the kernel. We need to write that target back to the
ioctl buffer and update the flags bits so that if the wait is
interrupted by a signal, when it is re-started, it will target
precisely the same vblank count as before.

* Leave driver API with 32-bit vblank count

v3:

* Rebase on top of Arnd Bergmann's patch which had
the switch to ktime_t parts.

[airlied: fix conflict with Ville vblank change].

Suggested-by: Michel Dänzer <michel@daenzer.net>
Suggested-by: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
(cherry picked from commit 2affbc16983e4fc90960bc7f70e7615f4228199b)

drm: vblank: use ktime_t instead of timeval

The drm vblank handling uses 'timeval' to store timestamps in either
monotonic or wall-clock time base. In either case, it reads the current
time as a ktime_t in get_drm_timestamp() and converts it from there.

This is a bit suspicious, as users of 'timeval' often suffer from
the time_t overflow in y2038. I have gone through this code and
found that it is unlikely to cause problems here:

- The user space ABI does not use time_t or timeval, but uses
'u32' and 'long' as the types. This means at least that rebuilding
user programs against a new libc with 64-bit time_t does not
change the ABI.

- As of commit c61eef726a78 ("drm: add support for monotonic vblank
timestamps") in linux-3.8, the monotonic timestamp is the default
and can only get reverted to wall-clock through a module-parameter.

- With the default monotonic timestamps, there is no problem at all.

- The drm_wait_vblank_ioctl() interface is alway safe on 64-bit
architectures, on 32-bit it might overflow the 'long' timestamps
in 2038 with wall-clock timestamps.

- The event handling uses 'u32' seconds, which overflow in 2106
on both 32-bit and 64-bit machines, when wall-clock timestamps
are used.

- The effect of overflowing either of the two is only temporary
(during the overflow, and is likely to keep working again
afterwards. It is likely the same problem as observing a
'settimeofday()' call, which was the reason for moving to the
monotonic timestamps in the first place.

Overall, this seems good enough, so my patch removes the use of
'timeval' from the vblank handling altogether and uses ktime_t
consistently, except for the part where we copy the data to user
space structures in the existing format.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Reviewed-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drm/vblank: Unexport drm_vblank_cleanup

There's no reason for drivers to call this, and all the ones I've
removed looked very fishy:
- Proper quiescenting of the vblank machinery should be done by
calling drm_crtc_vblank_off(), which is best done by shutting down
the entire display engine with drm_atomic_helper_shutdown.

- Releasing of allocated memory is done by the core already, it calls
drm_vblank_cleanup as a fallback.

- drm_vblank_cleanup also has checks for drivers which forget to clean
up vblank interrupts.

This essentially reverts

commit e77cef9c2d87db835ad9d70cde4a9b00b0ca2262
Author: Jerome Glisse <jglisse@redhat.com>
Date: Thu Jan 7 15:39:13 2010 +0100

drm: Avoid calling vblank function is vblank wasn't initialized

which was done to fix a bug in radeon code with msi interrupts:

commit 003e69f9862bcda89a75c27750efdbc17ac02945
Author: Jerome Glisse <jglisse@redhat.com>
Date: Thu Jan 7 15:39:14 2010 +0100

drm/radeon/kms: Don't try to enable IRQ if we have no handler installed

Afaict from digging around in old code, this was needed to avoid
blowing up in the ums fallback, and has stopped serving it's purpose
long ago - if irq init fails, the driver fails to load, and there's
really no way to blow up anymore.

Long story short, this was most likely a small ums compat/fallback
hack that became a thing of it's own and got cargo-cult duplicated all
over the drm codebase for essentially no gain at all.

v2: Mention that for drivers with a ->release callback cleanup is
handled by drm_dev_fini() (Thierry).

Cc: Thierry Reding <treding@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170626161949.25629-2-daniel.vetter@ffwll.ch

drm/vblank: Consistent drm_crtc_ prefix

We use drm_crtc_ for all the new-style vblank functions which directly
take a struct drm_crtc *. drm_accurate_vblank_count was the odd one
out, correct this to appease my OCD.

Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170524145212.27837-13-daniel.vetter@ffwll.ch

drm: Extract drm_vblank.[hc]

drm_irq.c contains both the irq helper library (optional) and the
vblank support (optional, but part of the modeset uapi, and doesn't
require the use of the irq helpers at all.

Split this up for more clarity of the scope of the individual bits.

v2: Move misplaced hunks to this patch (Stefan).

Cc: Stefan Agner <stefan@agner.ch>
Reviewed-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170531092146.12528-1-daniel.vetter@ffwll.ch