AFAICT i9xx_pfit_disable() on the GMCH display crtc disable path in
i9xx_crtc_disable() will always disable the panel fitter by writing 0 to
PFIT_CONTROL. The register save will always save/restore 0. Also we
completely recompue both in intel_gmch_panel_fitting so there's no way
we depend upon leftover bits.

Move the PFIT_CONTROL and PFIT_PGM_RATIOS save/restore to UMS
code. While at it, save/restore them both under the same conditions.
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
[danvet: Make it a bit clearer that we nowhere depend upon these
bits.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The block was added for spin_lock_irqsave flags, but since the locking
was converted to spin_lock_irq variant, the block is no longer needed.
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Since RSTDBYCTL is only saved on non-KMS path in within i915_save_state,
move the restore in i915_restore_state for symmetry.
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Don't save the panel power sequencer register on vlv/chv for two simple
reasons. First, these are the wrong registers to save to begin
with. Second, they are not restored anyway.
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

As per latest pm guide, we need to do this also on
past hsw.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Following the legacy ring submission example, update the
ring->init_context() hook to support the execlist submission mode.

v2: update to use the new workaround macros and cleanup unused code.
This takes care of both bdw and chv workarounds.

v2.1: Add missing call to init_context() during deferred context creation.

v3: Split init_context (emit) in legacy/lrc modes. For lrc, get the ringbuf
from the context (Mika/Daniel).

v4: Merge init_context interfaces back, the legacy mode only needs the ring,
but the lrc mode needs the ring and context (Mika).

Issue: VIZ-4092
Issue: GMIN-3475
Change-Id: Ie3d093b2542ab0e2a44b90460533e2f979788d6c
Cc: Deepak S <deepak.s@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: NMichel Thierry <michel.thierry@intel.com>
Signed-off-by: NArun Siluvery <arun.siluvery@linux.intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
[danvet: Align function paramater lists properly.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

When reading a CCK register we should obviously read it from CCK not
Punit. This problem has been present ever since this of code was
introduced in

 commit 67c3bf6f
 Author: Deepak S <deepak.s@linux.intel.com>
 Date:   Thu Jul 10 13:16:24 2014 +0530

    drm/i915: populate mem_freq/cz_clock for chv

The problem was raised during review by Mika [1] but somehow slipped
through the cracks, and the patch got applied with the problem unfixed.

[1] http://lists.freedesktop.org/archives/intel-gfx/2014-July/048937.html

Cc: Deepak S <deepak.s@linux.intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NDeepak S <deepak.s@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The predicate source registers are needed to implement conditional
rendering without stalling. The two source registers are used to load
the previous values of the PS_DEPTH_COUNT register saved from
PIPE_CONTROL commands. These can then be compared and used to set the
predicate enable bit via the MI_PREDICATE command.

The command parser version number is increased to 2 to make it easier
to detect the new functionality in user space.
Signed-off-by: NNeil Roberts <neil@linux.intel.com>
Reviewed-by: Brad Volkin <bradley.d.volkin@intel.com> (v1)
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org> (v1)
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This only affects the fastboot path as-is.  In that case, we simply need
to make sure that we update the pipe size at the first mode set.  Rather
than putting it off until we decide to flip (if indeed we do end up
flipping), update the pipe size as appropriate a bit earlier in the
set_config call.

This sets us up for better pipe tracking in later patches.
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

If these change (e.g. after a modeset following a fastboot), we need to
do a full mode set.

v2:
  - put under pipe_config check so we don't deref a null state (Jesse)
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This is useful for checking things later.

v2:
  - fix hsw infoframe enabled check (Ander)
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
[danvet: Add the missing PIPE_CONF_CHECK_I(has_infoframe); line to the
hw state cross-checker.]
[danet: Squash in fixup from Jesse to correctly compute has_infoframe
in the hdmi compute_config function.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This will allow us to consult more info before deciding whether to flip
or do a full mode set.

v2:
  - don't use uninitialized or incorrect pipe masks in set_config
    failure path (Ander)
v3:
  - fixup for pipe_config changes in compute_config (Jesse)
v4:
  - drop spurious hunk in force restore path (Ander)
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This allows us to calculate the full pipe config before we do any mode
setting work.

v2:
  - clarify comments about global vs. per-crtc mode set (Ander)
  - clean up unnecessary pipe_config = NULL setting (Ander)
v3:
  - fix pipe_config handling (alloc in compute_config, free in set_mode) (Jesse)
  - fix arg order in set_mode (Jesse)
  - fix failure path of set_config (Ander)
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Now that the backlight device no longer gets registered too early we
should be able to drop most of the INVALID_PIPE checks from the backlight
code.

The only exceptio is the opregion stuff where we may (in theory at
least) get a request from the BIOS already during driver init as soon as
the backlight setup has been done. In which case we can still get the
INVALID_PIPE from intel_get_pipe_from_connector(). So leave that check
in place, and add a comment explaining why.

For the rest, if we still manage to get here with INVALID_PIPE on
VLV/CHV we will now get a WARN from the lower level functions and
can then actually investigate further.

v2: Leave the check in the BIOS related code (Jani)

Cc: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Currently we register the backlight device as soon as we register the
connector. That means we can get backlight requests from userspace
already before reading out the current modeset hardware state.

That means we don't yet know the current crtc->encoder->connector mapping,
which causes problems for VLV/CHV which need to know the current pipe in
order to figure out which BLC registers to poke. Currently we just
ignore such requests fairly deep in the backlight code which means the
backlight device brightness property will get out of sync with our
backlight.level and the actual hardware state.

Fix the problem by delaying the backlight device registration until the
entire modeset init has been performed. And we also move the
backlight unregisteration to happen as the first thing during the
modeset cleanup so that we also won't be bothered with userspace
backlight requested during teardown.

This is a real world problem on machines using systemd, because systemd,
for some reason, wants to restore the backlight to the level it used last
time. And that happens as soon as it sees the backlight device appearing
in the system. Sometimes the userspace access makes it through before
the modeset init, sometimes not.

v2: Do not lie to the user in the debug prints (Jani)
    Include connector name in the prints (Jani)
    Fix a typo in the commit message (Jani)
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

On VLV/CHV both pipes A and B have their own backlight control
registers. In order to correctly read out the current hardware state at
init we need to know which pipe is driving the eDP port. Pass that
information down from the eDP init code into the backlight code.

To determine the correct pipe we first look at which pipe is currently
configured in the port control register, if that look invalid we look
at which pipe's PPS is currently controlling the port, and if that
too looks invalid we just assume pipe A.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

If the connector would have an encoder but the encoder didn't have a
crtc we might dereference a NULL crtc here. I suppose that should never
happen due to intel_sanitize_encoder(), but let's be a bit paranoid
print a warning if we ever hit this and return INVALID_PIPE to the
caller.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

On VLV/CHV when the display is off, we can't read out the current
backlight level from the hardware since we have no pipe to do so.
Currently we end up reading a bigus register due to passing
INVALID_PIPE to VLV_BLC_PWM_CTL().

Skip the entire .get_backlight() call if the backlight isn't enabled
according to backlight.enabled.

This problem can be reproduced simply by reading the backlight device
actual_brightness file while the display is off.

Cc: Jani Nikula <jani.nikula@intel.com>
Suggested-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

VLV/CHV have backlight controls only on pipes A and B. Bail out
without touching registers that don't exist, and print a warning.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Currently objects for which the hardware needs a contiguous physical
address are allocated a shadow backing storage to satisfy the contraint.
This shadow buffer is not wired into the normal obj->pages and so the
physical object is incoherent with accesses via the GPU, GTT and CPU. By
setting up the appropriate scatter-gather table, we can allow userspace
to access the physical object via either a GTT mmaping of or by rendering
into the GEM bo. However, keeping the CPU mmap of the shmemfs backing
storage coherent with the contiguous shadow is not yet possible.
Fortuituously, CPU mmaps of objects requiring physical addresses are not
expected to be coherent anyway.

This allows the physical constraint of the GEM object to be transparent
to userspace and allow it to efficiently render into or update them via
the GTT and GPU.

v2: Fix leak of pci handle spotted by Ville
v3: Remove the now duplicate call to detach_phys_object during free.
v4: Wait for rendering before pwrite. As this patch makes it possible to
render into the phys object, we should make it correct as well!
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Paulo noticed that we don't support RPS on GEN9 yet, so WARN for and
ignore any RPS interrupts on that platform.
Signed-off-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The logical place for these functions is in i915_irq.c next to the rest of
PM interrupt handling functions.

No functional change.
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The GEN6 and GEN8 versions differ only in the PM IIR and IER register
addresses and that on GEN8 we need to keep the
GEN8_PMINTR_REDIRECT_TO_NON_DISP PM interrupt unmasked. Abstract away
these 3 things in the GEN6 versions of the helpers and use them
everywhere.

No functional change.
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

After the previous patch the GEN8 RPS handler became very similar to the
GEN6 version, so unify the two functions.

No functional change.
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
[danvet: Move one misplaced hunk from a later patch to fix a bisect
issue as reported by Wu Fengguang's 0-day builder and fix suggested by
Imre.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The helpers to enable/disable PM IRQs for GEN6 and GEN8 are the same
except for the PM interrupt mask register, so abstract away this
register in the GEN6 versions and use these everywhere.

No functional change.
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

+WaForceEnableNonCoherent:chv
+WaHdcDisableFetchWhenMasked:chv

For: VIZ-4090
Signed-off-by: NArun Siluvery <arun.siluvery@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

WaDisablePartialInstShootdown:chv and
WaDisableThreadStallDopClockGating:chv are related to the same
register so combine them.
Signed-off-by: NArun Siluvery <arun.siluvery@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

-WaDisableDopClockGating:chv
-WaDisableSamplerPowerBypass:chv
-WaDisableGunitClockGating:chv
-WaDisableFfDopClockGating:chv
-WaDisableDopClockGating:chv

v2: Remove pre-production WA instead of restricting them
based on revision id (Ville)

For: VIZ-4090
Signed-off-by: NArun Siluvery <arun.siluvery@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Commit "drm/i915: create a prepare phase for sprite plane updates"
changed the old_obj pointer we use when committing sprite planes,
which caused a WARN() and a BUG() to be triggered. Later, commit
"drm/i915: use intel_fb_obj() macros to assign gem objects" introduced
the same problem to function intel_commit_sprite_plane().

Regression introduced by:
    commit ec82cb793c9224e0692eed904f43490cf70e8258
    Author: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
    Date:   Fri Oct 24 14:51:32 2014 +0100
        drm/i915: create a prepare phase for sprite plane updates
and:
    commit 77cde952
    Author: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
    Date:   Fri Oct 24 14:51:33 2014 +0100
        drm/i915: use intel_fb_obj() macros to assign gem objects

Credits to Imre Deak for pointing out the exact lines that were wrong.

v2: Also fix intel_commit_sprite_plane() (Ville)

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=85634
Testcase: igt/pm_rpm/legacy-planes
Testcase: igt/pm_rpm/legacy-planes-dpms
Testcase: igt/pm_rpm/universal-planes
Testcase: igt/pm_rpm/universal-planes-dpms
Credits-to: Imre Deak <imre.deak@intel.com>
Cc: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

- ppgtt init/release: these tracepoints are useful for observing the
  creation and destruction of Full PPGTTs.

- ctx create/free: we can use the ctx_free trace in combination with the
  ppgtt_release one to be sure that the ppgtt doesn't stay alive for too
  long after the ctx is destroyed. ctx_create is there for simmetry

- switch_mm: important point in the lifetime of the vm

v4: add DOC information
v5: pull the DOC in drm.tmpl
v6: clean ppgtt init/release traces + add ctx create/free and switch_mm
    tracepoints (Chris)
v7: drop execlist_submit_context tracepoint

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The Baseline_ELD_Len field does not include ELD Header Block size.

From High Definition Audio Specification, Revision 1.0a:

	The header block is a fixed size of 4 bytes. The baseline block
	is variable size in multiple of 4 bytes, and its size is defined
	in the header block Baseline_ELD_Len field (in number of
	DWords).

Do not include the header size in Baseline_ELD_Len field. Fix all known
users of eld[2].

While at it, switch to DIV_ROUND_UP instead of open coding it.
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Acked-by: NBen Skeggs <bskeggs@redhat.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Acked-by: NDave Airlie <airlied@linux.ie>
[danvet: Fix compile fail in nouveau.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Since a8bb6818 __intel_framebuffer_create() is called
with struct_mutex held, so it should use drm_gem_object_unreference()
instead of drm_gem_object_unreference_unlocked().

Found by Linux Driver Verification project (linuxtesting.org).

This regression has been introduced in

commit a8bb6818
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Mon Feb 10 18:00:39 2014 +0100

    drm/i915: Fix error path leak in fbdev fb allocation
Signed-off-by: NAlexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Use the new pipe config values to calculate the updated pll dividers.

This regression was introduced in

commit 0dbdf89f27b17ae1eceed6782c2917f74cbb5d59
Author: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Date:   Wed Oct 29 11:32:33 2014 +0200

    drm/i915: Add infrastructure for choosing DPLLs before disabling crtcs

	and

	commit 00d958817dd3daaa452c221387ddaf23d1e4c06f
	Author: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
	Date:   Wed Oct 29 11:32:36 2014 +0200

	    drm/i915: Covert remaining platforms to choose DPLLS before disabling CRTCs

v2: Use intel_pipe_will_have_type() to look at new configuration - Ander
Signed-off-by: NBob Paauwe <bob.j.paauwe@intel.com>
CC: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Tested-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The cleanup path would reset pll->new_config to NULL but wouldn't free
the allocated memory.
Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

for the Brothers in Triage
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We need the HPLL frequency when calculating cdclk. Currently we read
that out from the hardware every single time, which isn't going to fly
very well if the device is runtime suspended. So cache the HPLL
frequency in dev_priv and use the cached value.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reference: https://bugs.freedesktop.org/show_bug.cgi?id=82939Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This reverts commit 5cb13c07.

While the relevance for WaRsDontPollForAckOnClearingFWBits is under
investigation, revert this as regression.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=85684Tested-by: NTested-by: lu hua <huax.lu@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: S, Deepak <deepak.s@intel.com>
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This simplifies the code quite a bit compared to iterating over all
rings during the ring interrupt.

Also, it allows us to drop the mmio_flip spinlock, since the mmio_flip
struct is only accessed in two places. The first is when the flip is
queued and the other when the mmio writes are done. Since a flip cannot
be queued while there is a pending flip, the two paths shouldn't ever
run in parallel. We might need to revisit that if support for replacing
flips is implemented though.

v2: Don't hold dev->struct_mutext while waiting (Chris)

v3: Make the wait uninterruptable (Chris)
Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

So that it can be used by the flip code to wait for rendering without
holding any locks.
Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>