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path: root/drivers/gpu/drm/drm_irq.c
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2019-05-27drm: drop use of drmP.h in drm/*Sam Ravnborg
The use of the drmP.h header file is deprecated. Remove use from all files in drm/* so people do not look there and follow a bad example. Build tested allyesconfig,allmodconfig on x86, arm etc. Including alpha that is as always more challenging than the rest. Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Acked-by: Daniel Vetter <daniel@ffwll.ch> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Maxime Ripard <maxime.ripard@bootlin.com> Cc: Sean Paul <sean@poorly.run> Cc: David Airlie <airlied@linux.ie> Link: https://patchwork.freedesktop.org/patch/msgid/20190526173535.32701-8-sam@ravnborg.org
2019-04-24drm: allow removal of legacy codepaths (v4.1)Dave Airlie
If you don't want the legacy drivers, then lets get rid of all the legacy codepaths from the core module. This drop the size of drm.ko for me by about 10%. 380515 7422 4192 392129 5fbc1 ../../drm-next-build/drivers/gpu/drm/drm.ko 351736 7298 4192 363226 58ada ../../drm-next-build/drivers/gpu/drm/drm.ko v2: drop drm_lock as well, fix some DMA->DRM typos v3: avoid ifdefs in mainline code v4: rework ioctl defs v4.1: fix nouveau Kconfig Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Dave Airlie <airlied@redhat.com>
2019-01-29drm/irq: Ditch DRIVER_IRQ_SHAREDDaniel Vetter
This is only used by drm_irq_install(), which is an optional helper. For legacy pci devices this is required (due to interrupt sharing without msi/msi-x), and just making this the default exactly matches the behaviour of all existing drivers using the drm_irq_install() helpers. In case that ever becomes wrong drivers can roll their own irq handling, as many drivers already do (for other reasons like needing a threaded interrupt handler, or having an entire pile of different interrupt sources). v2: Rebase v3: Improve commit message (Emil) Cc: Sam Ravnborg <sam@ravnborg.org> Reviewed-by: Emil Velikov <emil.velikov@collabora.com> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20190129104248.26607-3-daniel.vetter@ffwll.ch
2019-01-29drm/irq: Don't check for DRIVER_HAVE_IRQ in drm_irq_(un)installDaniel Vetter
If a non-legacy driver calls these it's valid to assume there is interrupt support. The flag is really only needed for legacy drivers, which control IRQ enabling/disabling through the DRM_IOCTL_CONTROL legacy IOCTL. Also remove all the flag usage from non-legacy drivers. v2: Review from Emil: - improve commit message - I forgot hibmc, fix that Cc: linux-arm-kernel@lists.infradead.org Cc: intel-gfx@lists.freedesktop.org Cc: linux-amlogic@lists.infradead.org Cc: linux-arm-msm@vger.kernel.org Cc: freedreno@lists.freedesktop.org Cc: virtualization@lists.linux-foundation.org Cc: spice-devel@lists.freedesktop.org Cc: amd-gfx@lists.freedesktop.org Cc: linux-renesas-soc@vger.kernel.org Reviewed-by: Emil Velikov <emil.velikov@collabora.com> Reviewed-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20190129104248.26607-1-daniel.vetter@ffwll.ch
2018-09-14drm: Differentiate the lack of an interface from invalid parameterChris Wilson
If the ioctl is not supported on a particular piece of HW/driver combination, report ENOTSUP (aka EOPNOTSUPP) so that it can be easily distinguished from both the lack of the ioctl and from a regular invalid parameter. v2: Across all the kms ioctls we had a mixture of reporting EINVAL, ENODEV and a few ENOTSUPP (most where EINVAL) for a failed drm_core_check_feature(). Update everybody to report ENOTSUPP. v3: ENOTSUPP is an internal errno! It's value (524) does not correspond to a POSIX errno, the one we want is ENOTSUP. However, uapi/asm-generic/errno.h doesn't include ENOTSUP but man errno says "ENOTSUP and EOPNOTSUPP have the same value on Linux, but according to POSIX.1 these error values should be distinct." so use EOPNOTSUPP as its equivalent. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> #v2 Link: https://patchwork.freedesktop.org/patch/msgid/20180913192050.24812-1-chris@chris-wilson.co.uk
2017-06-01drm/doc: Polish irq helper documentationDaniel Vetter
Pull a (much shorter) overview into drm_irq.c, and instead put the callback documentation into in-line comments in drm_drv.h. v2: Move the include stanzas back to the split-up 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/20170531092253.12833-1-daniel.vetter@ffwll.ch
2017-06-01drm: Extract drm_vblank.[hc]Daniel Vetter
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
2017-05-10drm/vblank: Lock down vblank->hwmode moreDaniel Vetter
In the previous patch we've implemented hwmode tracking a la i915 for the vblank timestamp calculations. But that was just the basic semantics, i915 has some nice sanity checks to make sure we keep getting this right. Move them over too. v2: - WARN_ON_ONCE to avoid excessive spam (Ville) - Really only WARN on atomic drivers. Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Reviewed-by: Neil Armstrong <narmstrong@baylibre.com> Acked-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20170509140329.24114-5-daniel.vetter@ffwll.ch
2017-05-10drm/vblank: drop the mode argument from drm_calc_vbltimestamp_from_scanoutposDaniel Vetter
If we restrict this helper to only kms drivers (which is the case) we can look up the correct mode easily ourselves. But it's a bit tricky: - All legacy drivers look at crtc->hwmode. But that is updated already at the beginning of the modeset helper, which means when we disable a pipe. Hence the final timestamps might be a bit off. But since this is an existing bug I'm not going to change it, but just try to be bug-for-bug compatible with the current code. This only applies to radeon&amdgpu. - i915 tries to get it perfect by updating crtc->hwmode when the pipe is off (i.e. vblank->enabled = false). - All other atomic drivers look at crtc->state->adjusted_mode. Those that look at state->requested_mode simply don't adjust their mode, so it's the same. That has two problems: Accessing crtc->state from interrupt handling code is unsafe, and it's updated before we shut down the pipe. For nonblocking modesets it's even worse. For atomic drivers try to implement what i915 does. To do that we add a new hwmode field to the vblank structure, and update it from drm_calc_timestamping_constants(). For atomic drivers that's called from the right spot by the helper library already, so all fine. But for safety let's enforce that. For legacy driver this function is only called at the end (oh the fun), which is broken, so again let's not bother and just stay bug-for-bug compatible. The benefit is that we can use drm_calc_vbltimestamp_from_scanoutpos directly to implement ->get_vblank_timestamp in every driver, deleting a lot of code. v2: Completely new approach, trying to mimick the i915 solution. v3: Fixup kerneldoc. v4: Drop the WARN_ON to check that the vblank is off, atomic helpers currently unconditionally call this. Recomputing the same stuff should be harmless. v5: Fix typos and move misplaced hunks to the right patches (Neil). v6: Undo hunk movement (kbuild). Cc: Mario Kleiner <mario.kleiner@tuebingen.mpg.de> Cc: Eric Anholt <eric@anholt.net> Cc: Rob Clark <robdclark@gmail.com> Cc: linux-arm-msm@vger.kernel.org Cc: freedreno@lists.freedesktop.org Cc: Alex Deucher <alexander.deucher@amd.com> Cc: Christian König <christian.koenig@amd.com> Cc: Ben Skeggs <bskeggs@redhat.com> Reviewed-by: Neil Armstrong <narmstrong@baylibre.com> Acked-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20170509140329.24114-4-daniel.vetter@ffwll.ch
2017-05-10drm/vblank: Switch to bool in_vblank_irq in get_vblank_timestampDaniel Vetter
It's overkill to have a flag parameter which is essentially used just as a boolean. This takes care of core + adjusting drivers. Adjusting the scanout position callback is a bit harder, since radeon also supplies it's own driver-private flags in there. v2: Fixup misplaced hunks (Neil). v3: kbuild says v1 was better ... Cc: Mario Kleiner <mario.kleiner@tuebingen.mpg.de> Cc: Eric Anholt <eric@anholt.net> Cc: Rob Clark <robdclark@gmail.com> Cc: linux-arm-msm@vger.kernel.org Cc: freedreno@lists.freedesktop.org Cc: Alex Deucher <alexander.deucher@amd.com> Cc: Christian König <christian.koenig@amd.com> Cc: Ben Skeggs <bskeggs@redhat.com> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Reviewed-by: Neil Armstrong <narmstrong@baylibre.com> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20170509140329.24114-2-daniel.vetter@ffwll.ch
2017-05-10drm/vblank: Switch drm_driver->get_vblank_timestamp to return a boolDaniel Vetter
There's really no reason for anything more: - Calling this while the crtc vblank stuff isn't set up is a driver bug. Those places alrready DRM_ERROR. - Calling this when the crtc is off is either a driver bug (calling drm_crtc_handle_vblank at the wrong time) or a core bug (for anything else). Again, we DRM_ERROR. - EINVAL is checked at higher levels already, and if we'd use struct drm_crtc * instead of (dev, pipe) it would be real obvious that those are again core bugs. The only valid failure mode is crap hardware that couldn't sample a useful timestamp, to ask the core to just grab a not-so-accurate timestamp. Bool is perfectly fine for that. v2: Also fix up the one caller, I lost that in the shuffling (Jani). v3: Fixup commit message (Neil). Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Mario Kleiner <mario.kleiner@tuebingen.mpg.de> Cc: Eric Anholt <eric@anholt.net> Cc: Rob Clark <robdclark@gmail.com> Cc: linux-arm-msm@vger.kernel.org Cc: freedreno@lists.freedesktop.org Cc: Alex Deucher <alexander.deucher@amd.com> Cc: Christian König <christian.koenig@amd.com> Cc: Ben Skeggs <bskeggs@redhat.com> Reviewed-by: Neil Armstrong <narmstrong@baylibre.com> Acked-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20170509140329.24114-1-daniel.vetter@ffwll.ch
2017-04-04drm: Pass CRTC ID in userspace vblank eventsAnder Conselvan de Oliveira
With the atomic API, it is possible that a single commit affects multiple crtcs. If the user requests an event with that commit, one event will be sent for each CRTC, but it is not possible to distinguish which crtc an event is for in user space. To solve this, the reserved field in struct drm_vblank_event is repurposed to include the crtc_id which the event is for. The DRM_CAP_CRTC_IN_VBLANK_EVENT is added to allow userspace to query if the crtc field will be set properly. [daniels: Rebased, using Maarten's forward-port.] Signed-off-by: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com> Signed-off-by: Daniel Stone <daniels@collabora.com> Cc: Maarten Lankhorst <maarten.lankhorst@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20170404165221.28240-2-daniels@collabora.com
2017-03-30drm: Convert cmpxchg(bool) back to a two step operationChris Wilson
ARM v6 (at least) only allows cmpxchg on 32bit variables which doesn't always include the bool type. drivers/built-in.o: In function `vblank_disable_and_save': imx-ocotp.c:(.text+0xb45e8): undefined reference to `__bad_cmpxchg' Makefile:986: recipe for target 'vmlinux' failed Reported-by: kbuild test robot <fengguang.wu@intel.com> Reported-by: Leonard Crestez <leonard.crestez@nxp.com> Fixes: 43dc7fe2b211 ("drm: Mark up accesses of vblank->enabled outside of its spinlock") Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20170330140832.32377-1-chris@chris-wilson.co.uk
2017-03-29drm: Peek at the current counter/timestamp for vblank queriesChris Wilson
Bypass all the spinlocks and return the last timestamp and counter from the last vblank if the driver delcares that it is accurate (and stable across on/off), and the vblank is currently enabled. This is dependent upon the both the hardware and driver to provide the proper barriers to facilitate reading our bookkeeping outside of the vblank interrupt and outside of the explicit vblank locks. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Michel Dänzer <michel@daenzer.net> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Cc: Dave Airlie <airlied@redhat.com>, Cc: Mario Kleiner <mario.kleiner.de@gmail.com> Link: http://patchwork.freedesktop.org/patch/msgid/20170317202030.24410-4-chris@chris-wilson.co.uk Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
2017-03-29drm: Refactor vblank sequence number comparisonChris Wilson
Move the repeated (a - b) <= (1 << 23) to its own function. v2: Catch the '1<<23' inside drm_handle_vblank() as well Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Michel Dänzer <michel@daenzer.net> Link: http://patchwork.freedesktop.org/patch/msgid/20170322100650.26082-1-chris@chris-wilson.co.uk Reviewed-by: Michel Dänzer <michel.daenzer@amd.com> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
2017-03-29drm: vblank cannot be enabled if dev->irq_enabled is falseChris Wilson
Since we cannot enable the vblank if !dev->irq_enabled, we assert that checking for both !vblank->enabled and !dev->irq_enabled is tautological and only need the former. The only time it may differ is when racing with drm_irq_uninstall(), but that will then disable the vblank and wakeup the waiters. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Link: http://patchwork.freedesktop.org/patch/msgid/20170317202030.24410-2-chris@chris-wilson.co.uk Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
2017-03-29drm: Mark up accesses of vblank->enabled outside of its spinlockChris Wilson
Order the update to vblank->enabled after the timestamp is primed so that a concurrent unlocked reader will only see the vblank->enabled with the current timestamp. v2: vblank->enable is guarded by dev->vbl_lock not dev->vblank_time_lock, update the READ_ONCE accordingly. Do not add a READ_ONCE(vblank->enabled) inside the interrupt handler to avoid missing an interrupt whilst racing with enable_vblank() Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Link: http://patchwork.freedesktop.org/patch/msgid/20170317202030.24410-1-chris@chris-wilson.co.uk Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
2017-03-29drm: Make the decision to keep vblank irq enabled earlierChris Wilson
We want to provide the vblank irq shadow for pageflip events as well as vblank queries. Such events are completed within the vblank interrupt handler, and so the current check for disabling the irq will disable it from with the same interrupt as the last pageflip event. If we move the decision on whether to disable the irq (based on there no being no remaining vblank events, i.e. vblank->refcount == 0) to before we signal the events, we will only disable the irq on the interrupt after the last event was signaled. In the normal course of events, this will keep the vblank irq enabled for the entire flip sequence whereas before it would flip-flop around every interrupt. v2: Move the disable_fn() call outside of the vblank_event_lock. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Michel Dänzer <michel@daenzer.net> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Cc: Dave Airlie <airlied@redhat.com>, Cc: Mario Kleiner <mario.kleiner.de@gmail.com> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> #v1 Reviewed-by: Mario Kleiner <mario.kleiner.de@gmail.com> #v1 Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20170324173058.23051-1-chris@chris-wilson.co.uk
2017-03-25drm/vblank: Remove DRM_VBLANKTIME_IN_VBLANKDaniel Vetter
The core code doesn't care at all about this, it's entirely dead. Cc: Mario Kleiner <mario.kleiner@tuebingen.mpg.de> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20170322083617.13361-11-daniel.vetter@ffwll.ch
2017-03-16drm: Skip the waitqueue setup for vblank queriesChris Wilson
Avoid adding to the waitqueue and reprobing the current vblank if the caller is only querying the current vblank sequence and timestamp, where we know that the wait would return immediately. v2: Add CRTC identifier to debug messages Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Michel Dänzer <michel@daenzer.net> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Cc: Dave Airlie <airlied@redhat.com>, Cc: Mario Kleiner <mario.kleiner.de@gmail.com> Reviewed-by: Michel Dänzer <michel@daenzer.net> Reviewed-and-tested-by: Mario Kleiner <mario.kleiner.de@gmail.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: http://patchwork.freedesktop.org/patch/msgid/20170315204027.20160-2-chris@chris-wilson.co.uk
2017-03-16drm: Defer disabling the vblank IRQ until the next interrupt (for instant-off)Chris Wilson
On vblank instant-off systems, we can get into a situation where the cost of enabling and disabling the vblank IRQ around a drmWaitVblank query dominates. And with the advent of even deeper hardware sleep state, touching registers becomes ever more expensive. However, we know that if the user wants the current vblank counter, they are also very likely to immediately queue a vblank wait and so we can keep the interrupt around and only turn it off if we have no further vblank requests queued within the interrupt interval. After vblank event delivery, this patch adds a shadow of one vblank where the interrupt is kept alive for the user to query and queue another vblank event. Similarly, if the user is using blocking drmWaitVblanks, the interrupt will be disabled on the IRQ following the wait completion. However, if the user is simply querying the current vblank counter and timestamp, the interrupt will be disabled after every IRQ and the user will enabled it again on the first query following the IRQ. v2: Mario Kleiner - After testing this, one more thing that would make sense is to move the disable block at the end of drm_handle_vblank() instead of at the top. Turns out that if high precision timestaming is disabled or doesn't work for some reason (as can be simulated by echo 0 > /sys/module/drm/parameters/timestamp_precision_usec), then with your delayed disable code at its current place, the vblank counter won't increment anymore at all for instant queries, ie. with your other "instant query" patches. Clients which repeatedly query the counter and wait for it to progress will simply hang, spinning in an endless query loop. There's that comment in vblank_disable_and_save: "* 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. */ With the disable happening after leading edge of vblank (== hw counter increment already happened) but before the vblank counter/timestamp handling in drm_handle_vblank, that step is needed to keep the counter progressing, so skipping it is bad. Now without high precision timestamping support, a kms driver must not set dev->vblank_disable_immediate = true, as this would cause problems for clients, so this shouldn't matter, but it would be good to still make this robust against a future kms driver which might have unreliable high precision timestamping, e.g., high precision timestamping that intermittently doesn't work. v3: Patch before coffee needs extra coffee. Testcase: igt/kms_vblank Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Michel Dänzer <michel@daenzer.net> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Cc: Dave Airlie <airlied@redhat.com>, Cc: Mario Kleiner <mario.kleiner.de@gmail.com> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: http://patchwork.freedesktop.org/patch/msgid/20170315204027.20160-1-chris@chris-wilson.co.uk
2017-03-14drm: Remove drm_pending_event->pidDaniel Vetter
We might as well dump the drm_file pointer, that's about as useful a cookie as the pid. Noticed while typing docs for drm_file and friends. Since the only consumer of this is the tracepoints I think we can safely change this - those tracepoints should not be uapi relevant at all. It all goes back to commit b9c2c9ae882f058084e13e339925dbf8d2d20271 Author: Jesse Barnes <jbarnes@virtuousgeek.org> Date: Thu Jul 1 16:48:09 2010 -0700 drm: add per-event vblank event trace points which doesn't give a special justification for using pid over a pointer. Also note that the nouveau code setting it is entirely pointless: Since this isn't a vblank event, it will never hit the vblank tracepoints. Cc: Ben Skeggs <bskeggs@redhat.com> Reviewed-by: Sean Paul <seanpaul@chromium.org> Reviewed-by: Liviu Dudau <Liviu.Dudau@arm.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: http://patchwork.freedesktop.org/patch/msgid/20170308141257.12119-11-daniel.vetter@ffwll.ch
2017-02-07drm: unexport function drm_vblank_no_hw_counter()Shawn Guo
The function drm_vblank_no_hw_counter() is now only used in core vblank wrapper code. Let's unexport it by making it a static function. Signed-off-by: Shawn Guo <shawn.guo@linaro.org> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: http://patchwork.freedesktop.org/patch/msgid/1486458995-31018-4-git-send-email-shawnguo@kernel.org
2017-02-07drm: add vblank hooks to struct drm_crtc_funcsShawn Guo
The vblank is mostly CRTC specific and implemented as part of CRTC driver. Let's keep the vblank hooks struct drm_driver for legacy drivers, and add corresponding hooks in struct drm_crtc_funcs. These hooks take struct drm_crtc pointer as argument, and will be called by core vblank handling code for DRIVER_MODESET drivers. The new hooks get plugged into core by adding wrapper functions for vblank handling code. The .get_vblank_counter hook is effectively optional, as we provide drm_vblank_no_hw_counter() as the default fallback in the wrapper function. Signed-off-by: Shawn Guo <shawn.guo@linaro.org> Reviewed-by: Andrzej Hajda <a.hajda@samsung.com> Acked-by: Thierry Reding <treding@nvidia.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: http://patchwork.freedesktop.org/patch/msgid/1486458995-31018-2-git-send-email-shawnguo@kernel.org
2017-01-26drm: Nuke ums vgaarb supportDaniel Vetter
i915, nouveau (ever since merged to upstream) and radeon all lack ums support in upstream. No point keeping the ums vgaarb support around. Reviewed-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20170125062657.19270-12-daniel.vetter@ffwll.ch
2017-01-25drm/core: Use recommened kerneldoc for struct member refsDaniel Vetter
I just learned that &struct_name.member_name works and looks pretty even. It doesn't (yet) link to the member directly though, which would be really good for big structures or vfunc tables (where the per-member kerneldoc tends to be long). Also some minor drive-by polish where it makes sense, I read a lot of docs ... v2: Review from Gustavo. Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Gustavo Padovan <gustavo.padovan@collabora.com> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20170125062657.19270-6-daniel.vetter@ffwll.ch
2016-12-30drm/doc: use preferred struct reference in kernel-docDaniel Vetter
sed -e 's/\( \* .*\)struct &\([_a-z]*\)/\1\&struct \2/' -i Originally I wasnt a friend of this style because I thought a line-break between the "&struct" and "foo" part would break it. But a quick test shows that " * &struct \n * foo\n" works pefectly well with current kernel-doc. So time to mass-apply these changes! Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: David Herrmann <dh.herrmann@gmail.com> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/1483044517-5770-6-git-send-email-daniel.vetter@ffwll.ch
2016-12-18drm/irq: drm_legacy_ prefix for legacy ioctlsDaniel Vetter
Spotted while auditing our ioctl table. Also nuke the not-really-kerneldoc comments, we don't document internals and definitely don't want to mislead people with the old dragons. I think with this all the legacy ioctls now have proper drm_legacy_ prefixes. Reviewed-by: Sean Paul <seanpaul@chromium.org> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20161213230814.19598-2-daniel.vetter@ffwll.ch
2016-11-15drm/irq: Unexport drm_vblank_on/offDaniel Vetter
Only remaining use was in amdgpu, and trivial to convert over to drm_crtc_vblank_* variants. Cc: Alex Deucher <alexander.deucher@amd.com> Cc: Christian König <christian.koenig@amd.com> Reviewed-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20161114090255.31595-5-daniel.vetter@ffwll.ch
2016-11-15drm/irq: Unexport drm_vblank_countDaniel Vetter
No one outside of drm_irq.c should ever need this. The correct way to implement get_vblank_count for hw lacking a vblank counter is drm_vblank_no_hw_counter. Fix this up in mtk, which is the only offender left over. Cc: CK Hu <ck.hu@mediatek.com> Cc: Philipp Zabel <p.zabel@pengutronix.de> Acked-by: Philipp Zabel <p.zabel@pengutronix.de> Reviewed-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20161114090255.31595-4-daniel.vetter@ffwll.ch
2016-11-15drm/irq: Make drm_vblank_pre/post_modeset internalDaniel Vetter
Now that all drivers are switched over to drm_crtc_vblank_on/off we can relegate pre/post_modeset to the purely drm_irq.c internal role of supporting old ums userspace. As usual switch to the drm_legacy_ prefix to make it clear this is for old drivers only. v2: Rebase on top of Thierry's s/int crtc/unsigned int pipe/ changes. Cc: Ben Skeggs <bskeggs@redhat.com> Cc: Alex Deucher <alexander.deucher@amd.com> Reviewed-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
2016-10-18drm: avoid uninitialized timestamp use in wait_vblankArnd Bergmann
gcc warns about the timestamp in drm_wait_vblank being possibly used without an initialization: drivers/gpu/drm/drm_irq.c: In function 'drm_crtc_send_vblank_event': drivers/gpu/drm/drm_irq.c:992:24: error: 'now.tv_usec' may be used uninitialized in this function [-Werror=maybe-uninitialized] drivers/gpu/drm/drm_irq.c:1069:17: note: 'now.tv_usec' was declared here drivers/gpu/drm/drm_irq.c:991:23: error: 'now.tv_sec' may be used uninitialized in this function [-Werror=maybe-uninitialized] This can happen if drm_vblank_count_and_time() returns 0 in its error path. To sanitize the error case, I'm changing that function to return a zero timestamp when it fails. Fixes: e6ae8687a87b ("drm: idiot-proof vblank") Reviewed-by: David Herrmann <dh.herrmann@gmail.com> Cc: Rob Clark <robdclark@gmail.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Mario Kleiner <mario.kleiner.de@gmail.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: http://patchwork.freedesktop.org/patch/msgid/20161017221355.1861551-6-arnd@arndb.de
2016-10-04drm: Document caveats around atomic event handlingDaniel Vetter
It's not that obvious how a driver can all race the atomic commit with handling the completion event. And there's unfortunately a pile of drivers with rather bad event handling which misdirect people into the wrong direction. Try to remedy this by documenting everything better. v2: Type fixes Alex spotted. v3: More typos Alex spotted. Cc: Andrzej Hajda <a.hajda@samsung.com> Cc: Alex Deucher <alexdeucher@gmail.com> Reviewed-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/1475229896-6047-1-git-send-email-daniel.vetter@ffwll.ch
2016-08-16drm/doc: Fix more kerneldoc/sphinx warningsDaniel Vetter
These are the leftovers I could only track down using keep_warnings = True. For some of them we might want to update our style guide on how to reference structures and constants, not sure ... Cc: Markus Heiser <markus.heiser@darmarit.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Reviewed-by: Sean Paul <seanpaul@chromium.org> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/1471034937-651-1-git-send-email-daniel.vetter@ffwll.ch
2016-08-08drm: Make sure drm_vblank_no_hw_counter isn't abusedDaniel Vetter
Shouldn't be possible since everyone kzallocs this, but better safe than sorry. Random drive-by-idea really. Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Reviewed-by: Rodrigo Vivi <rdorigo.vivi@intel.com> Signed-off-by: Sean Paul <seanpaul@chromium.org> Link: http://patchwork.freedesktop.org/patch/msgid/1470673493-14304-1-git-send-email-daniel.vetter@ffwll.ch
2016-08-08drm: Used DRM_LEGACY for all legacy functionsDaniel Vetter
Except for nouveau, only legacy drivers need this really. And nouveau is already marked up with DRIVER_KMS_LEGACY_CONTEXT as the special case. I've tried to be careful to leave everything related to modeset still using the DRIVER_MODESET flag. Otherwise it's a direct replacement of !DRIVER_MODESET with DRIVER_LEGACY checks. Also helps readability since fewer negative checks overall. Reviewed-by: David Herrmann <dh.herrmann@gmail.com> Reviewed-by: Frank Binns <frank.binns@imgtec.com> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/1470251470-30830-2-git-send-email-daniel.vetter@ffwll.ch
2016-08-08drm: Avoid printing negative values for unsigned variables.Rodrigo Vivi
It was really strange to see negative vblank seqs on debug messages. It is rare to have that big number, but when it happens it is confusing and misleading. Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: http://patchwork.freedesktop.org/patch/msgid/1470243226-2750-1-git-send-email-rodrigo.vivi@intel.com
2016-07-19drm: Extract&Document drm_irq.hDaniel Vetter
The drm_irq docs want one function from drmP.h, but that one is a serious mess. Extract it, and while at it improve the docs a bit. There's a bit a header loop issue since core data structures like drm_device and drm_driver aren't in their own headers yet, which means the drm_irq.h include in drmP.h needs to be in just the right spot :( Also noticed that drm_vblank_crtc->last_wait is entirely unused, remove it. v2: git add drm_irq.h ... Acked-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
2016-07-12drm: make drm_vblank_count_and_time() staticGustavo Padovan
As they are not used anywhere outside drm_irq.c make them static. Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: http://patchwork.freedesktop.org/patch/msgid/1467677092-5089-1-git-send-email-gustavo@padovan.org
2016-07-12drm: Only handle _DRM_VBLANK_NEXTONMISS onceMichel Dänzer
Consolidate the _DRM_VBLANK_NEXTONMISS handling between drm_wait_vblank and drm_queue_vblank_event. This is a cleanup spotted while working on other changes. (The way it was previously handled could also theoretically result in drm_queue_vblank_event unnecessarily bumping vblwait->request.sequence, if the vblank counter happened to increment between the drm_vblank_count(_and_time) calls in each function, but that's unlikely) Signed-off-by: Michel Dänzer <michel.daenzer@amd.com> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: http://patchwork.freedesktop.org/patch/msgid/1466755187-29418-1-git-send-email-michel@daenzer.net
2016-06-27drm: fix some spelling mistakesFrank Binns
Signed-off-by: Frank Binns <frank.binns@imgtec.com> Reviewed-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Jani Nikula <jani.nikula@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/1466763337-27428-1-git-send-email-frank.binns@imgtec.com
2016-06-20drm: fix send_vblank_event use-after-free errorMatthew Auld
The drm_pending_event can be freed by drm_send_event_locked, as a result we should call trace_drm_vblank_event_delivered before this to avoid hitting a user-after-free error when accessing the pid member: [ 378.438497] BUG: KASAN: use-after-free in send_vblank_event+0xf0/0x310 [drm] at addr ffff8801ac7e50a0 [ 378.438500] Read of size 4 by task Xorg/1562 [ 378.438501] ============================================================================= [ 378.438504] BUG kmalloc-128 (Tainted: G B ): kasan: bad access detected [ 378.438506] ----------------------------------------------------------------------------- [ 378.438509] INFO: Freed in 0x10001309c age=18446737369265680575 cpu=0 pid=0 [ 378.438541] drm_send_event_locked+0x207/0x2f0 [drm] [ 378.438544] __slab_free+0x24c/0x650 [ 378.438546] kfree+0x3a2/0x760 [ 378.438578] drm_send_event_locked+0x207/0x2f0 [drm] [ 378.438610] send_vblank_event+0xb7/0x310 [drm] [ 378.438643] drm_crtc_send_vblank_event+0x130/0x1f0 [drm] [ 378.438722] intel_atomic_commit_tail+0x23b5/0x53f0 [i915] [ 378.438802] intel_atomic_commit+0xbae/0x12f0 [i915] [ 378.438839] drm_atomic_commit+0xb0/0x120 [drm] [ 378.438855] drm_atomic_helper_connector_dpms+0x339/0x5d0 [drm_kms_helper] [ 378.438891] drm_mode_obj_set_property_ioctl+0x8f1/0xcc0 [drm] [ 378.438927] drm_mode_connector_property_set_ioctl+0xf3/0x170 [drm] [ 378.438959] drm_ioctl+0x2d7/0xae0 [drm] [ 378.438962] do_vfs_ioctl+0x1c9/0x1280 [ 378.438964] SyS_ioctl+0x79/0x90 [ 378.438967] entry_SYSCALL_64_fastpath+0x1a/0xa4 Cc: dri-devel@lists.freedesktop.org Cc: Daniel Vetter <daniel.vetter@intel.com> Signed-off-by: Matthew Auld <matthew.auld@intel.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: http://patchwork.freedesktop.org/patch/msgid/1466440966-5410-1-git-send-email-matthew.auld@intel.com
2016-06-13drm: make drm_vblank_{get,put}() staticGustavo Padovan
As they are not used anywhere outside drm_irq.c make them static. Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: http://patchwork.freedesktop.org/patch/msgid/1465308482-15104-4-git-send-email-gustavo@padovan.org
2016-06-13drm: remove legacy drm_arm_vblank_event()Gustavo Padovan
We don't have any user of this function anymore, let's remove it. Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: http://patchwork.freedesktop.org/patch/msgid/1465308482-15104-3-git-send-email-gustavo@padovan.org
2016-06-13drm: remove legacy drm_send_vblank_event()Gustavo Padovan
We don't have any user of this function anymore, let's remove it. Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: http://patchwork.freedesktop.org/patch/msgid/1465308482-15104-2-git-send-email-gustavo@padovan.org
2016-06-03drm/doc: Drop kerneldoc for static functions in drm_irq.cDaniel Vetter
At least in drm core we only document the driver interfaces using kerneldoc. For internals an unstructured comment is good enough. Fixes a warning from kernel-doc, too. Acked-by: Liviu Dudau <Liviu.Dudau@arm.com> Acked-by: Jani Nikula <jani.nikula@intel.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: http://patchwork.freedesktop.org/patch/msgid/1464729075-22243-5-git-send-email-daniel.vetter@ffwll.ch
2016-06-02Merge branch 'drm-intel-next' of git://anongit.freedesktop.org/drm-intel ↵Dave Airlie
into drm-next drm-intel-next-2016-05-22: - cmd-parser support for direct reg->reg loads (Ken Graunke) - better handle DP++ smart dongles (Ville) - bxt guc fw loading support (Nick Hoathe) - remove a bunch of struct typedefs from dpll code (Ander) - tons of small work all over to avoid casting between drm_device and the i915 dev struct (Tvrtko&Chris) - untangle request retiring from other operations, also fixes reset stat corner cases (Chris) - skl atomic watermark support from Matt Roper, yay! - various wm handling bugfixes from Ville - big pile of cdclck rework for bxt/skl (Ville) - CABC (Content Adaptive Brigthness Control) for dsi panels (Jani&Deepak M) - nonblocking atomic commits for plane-only updates (Maarten Lankhorst) - bunch of PSR fixes&improvements - untangle our map/pin/sg_iter code a bit (Dave Gordon) drm-intel-next-2016-05-08: - refactor stolen quirks to share code between early quirks and i915 (Joonas) - refactor gem BO/vma funcstion (Tvrtko&Dave) - backlight over DPCD support (Yetunde Abedisi) - more dsi panel sequence support (Jani) - lots of refactoring around handling iomaps, vma, ring access and related topics culmulating in removing the duplicated request tracking in the execlist code (Chris & Tvrtko) includes a small patch for core iomapping code - hw state readout for bxt dsi (Ramalingam C) - cdclk cleanups (Ville) - dedupe chv pll code a bit (Ander) - enable semaphores on gen8+ for legacy submission, to be able to have a direct comparison against execlist on the same platform (Chris) Not meant to be used for anything else but performance tuning - lvds border bit hw state checker fix (Jani) - rpm vs. shrinker/oom-notifier fixes (Praveen Paneri) - l3 tuning (Imre) - revert mst dp audio, it's totally non-functional and crash-y (Lyude) - first official dmc for kbl (Rodrigo) - and tons of small things all over as usual * 'drm-intel-next' of git://anongit.freedesktop.org/drm-intel: (194 commits) drm/i915: Revert async unpin and nonblocking atomic commit drm/i915: Update DRIVER_DATE to 20160522 drm/i915: Inline sg_next() for the optimised SGL iterator drm/i915: Introduce & use new lightweight SGL iterators drm/i915: optimise i915_gem_object_map() for small objects drm/i915: refactor i915_gem_object_pin_map() drm/i915/psr: Implement PSR2 w/a for gen9 drm/i915/psr: Use ->get_aux_send_ctl functions drm/i915/psr: Order DP aux transactions correctly drm/i915/psr: Make idle_frames sensible again drm/i915/psr: Try to program link training times correctly drm/i915/userptr: Convert to drm_i915_private drm/i915: Allow nonblocking update of pageflips. drm/i915: Check for unpin correctness. Reapply "drm/i915: Avoid stalling on pending flips for legacy cursor updates" drm/i915: Make unpin async. drm/i915: Prepare connectors for nonblocking checks. drm/i915: Pass atomic states to fbc update functions. drm/i915: Remove reset_counter from intel_crtc. drm/i915: Remove queue_flip pointer. ...
2016-05-24drm: use seqlock for vblank time/countMatthew Auld
This patch aims to replace the roll-your-own seqlock implementation with full-blown seqlock'. We also remove the timestamp ring-buffer in favour of single timestamp/count pair protected by a seqlock. In turn this means we can now increment the vblank freely without the need for clamping. v2: - reduce the scope of the seqlock, keeping vblank_time_lock - make the seqlock per vblank_crtc, so multiple readers aren't blocked by the writer Cc: Mario Kleiner <mario.kleiner@tuebingen.mpg.de> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Matthew Auld <matthew.auld@intel.com> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Reviewed-by: Mario Kleiner <mario.kleiner.de@gmail.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: http://patchwork.freedesktop.org/patch/msgid/1462890088-18194-1-git-send-email-matthew.auld@intel.com
2016-05-21drm: Nuke ->vblank_disable_allowedDaniel Vetter
This was added in commit 0a3e67a4caac273a3bfc4ced3da364830b1ab241 Author: Jesse Barnes <jbarnes@virtuousgeek.org> Date: Tue Sep 30 12:14:26 2008 -0700 drm: Rework vblank-wait handling to allow interrupt reduction. to stay backwards-compatible with old UMS code that didn't even tell the kernel when it did a modeset, so that the kernel could save/restore vblank counters. At worst this means vblanks will be somewhat funky on a setup that very likely no one still runs. So let's just nuke it. Plan B would be to set it unconditionally in drm_vblank_init for kms drivers, instead of in each driver separately. So if this patch breaks anything please only restore the hunks in drmP.h and drm_irq.c, plus add a check for DRIVER_MODESET in drm_vblank_init. Stumbled over this in a discussion on irc with Chris. Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Alex Deucher <alexander.deucher@amd.com> Cc: Liviu Dudau <liviu.dudau@arm.com> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Eric Anholt <eric@anholt.net> Cc: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> Cc: Inki Dae <inki.dae@samsung.com> Cc: Tomi Valkeinen <tomi.valkeinen@ti.com> Cc: Mark Yao <mark.yao@rock-chips.com> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: Philipp Zabel <p.zabel@pengutronix.de> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Reviewed-by: Alex Deucher <alexander.deucher@amd.com> Acked-by: Liviu Dudau <Liviu.Dudau@arm.com> Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Tested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Dave Airlie <airlied@redhat.com>
2016-05-19drm/core: Add drm_accurate_vblank_count, v5.Maarten Lankhorst
This function is useful for gen2 intel devices which have no frame counter, but need a way to determine the current vblank count without racing with the vblank interrupt handler. intel_pipe_update_start checks if no vblank interrupt will occur during vblank evasion, but cannot check whether the vblank handler has run to completion. This function uses the timestamps to determine when the last vblank has happened, and interpolates from there. Changes since v1: - Take vblank_time_lock and don't use drm_vblank_count_and_time. Changes since v2: - Don't return time of last vblank. Changes since v3: - Change pipe to unsigned int. (Ville) - Remove unused documentation for tv_ret. (kbuild) Changes since v4: - Add warning to docs when the function is useful. - Add a WARN_ON when get_vblank_timestamp is unavailable. - Use drm_vblank_count. Cc: Mario Kleiner <mario.kleiner.de@gmail.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> #v4 Acked-by: David Airlie <airlied@linux.ie> #irc, v4 Link: http://patchwork.freedesktop.org/patch/msgid/1463490484-19540-2-git-send-email-maarten.lankhorst@linux.intel.com Reviewed-by: Mario Kleiner <mario.kleiner.de@gmail.com>