Rather than describing an object as either "snooped or LLC", we can do
better as we should know what machine we are running on!
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Chris has decided that enough is enough. It's time to fixup dev Vs
dev_priv. This is a modest contribution to the crusade.

v2: Still use INTEL_INFO(), for the (mythical!) case we want to hardcode
    the info struct with defines (Chris)
    Rename the macro argument from 'dev' to 'dev_priv' (Jani)

v3: Use names unlikely to be used as macro arguments (Chris)
Suggested-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The GEN6_PM* registers don't exist on BDW anymore, so when we read
this file we trigger unclaimed register errors. The equivalent BDW
register for PMs is GEN8_GT_I*R(2), so use it.

Testcase: igt/pm_rpm/debugfs-read
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This has turned out to be really handy in debug so far.

Update:
Since writing this patch, I've gotten similar code upstream for error
state. I've used it quite a bit in debugfs however, and I'd like to keep
it here at least until preemption is working.
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>

This patch was accidentally dropped in the first Execlists version, and
it has been very useful indeed. Put it back again, but as a standalone
debugfs file.
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>

v2: Take the device struct_mutex rather than mode_config mutex for
atomic state capture.
Signed-off-by: NThomas Daniel <thomas.daniel@intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
[danvet: Checkpatch.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

v2: Warn and return if LRCs are not enabled.

v3: Grab the Execlists spinlock (noticed by Daniel Vetter).
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>

v4: Lock the struct mutex for atomic state capture
Signed-off-by: NThomas Daniel <thomas.daniel@intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
[danvet: Checkpatch.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

There's a bit a confusion since we track the global gtt,
the aliasing and real ppgtt in the ctx->vm pointer. And not
all callers really bother to check for the different cases and just
presume that it points to a real ppgtt.

Now looking closely we don't actually need ->vm to always point at an
address space - the only place that cares actually has fixup code
already to decide whether to look at the per-proces or the global
address space.

So switch to just tracking the ppgtt directly and ditch all the
extraneous code.

v2: Fixup the ppgtt debugfs file to not oops on a NULL ctx->ppgtt.
Also drop the early exit - without aliasing ppgtt we want to dump all
the ppgtts of the contexts if we have full ppgtt.

v3: Actually git add the compile fix.
Reviewed-by: NMichel Thierry <michel.thierry@intel.com>
Cc: "Thierry, Michel" <michel.thierry@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
OTC-Jira: VIZ-3724
[danvet: Resolve conflicts with execlist patches while applying.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Hardware contexts reference a ppgtt, not the other way round. And the
only user of this (in debugfs) actually only cares about which file
the ppgtt is associated with. So give it what it wants.

While at it give the ppgtt create function a proper name&place.
Reviewed-by: NMichel Thierry <michel.thierry@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Currently, if the machine is runtime suspended an you read the file,
you will get an "Unclaimed register" error message.

Testcase: igt/pm_rpm/debugfs-read
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Following the established idom, let's provide a macro to iterate through
the encoders.

spatch helps, once more, for the substitution:

  @@
  iterator name list_for_each_entry;
  iterator name for_each_intel_encoder;
  struct intel_encoder * encoder;
  struct drm_device * dev;
  @@
  -list_for_each_entry(encoder, &dev->mode_config.encoder_list, base.head) {
  +for_each_intel_encoder(dev, encoder) {
    ...
  }

I also modified a few call sites by hand where a pointer to mode_config
was directly used (to avoid overflowing 80 chars).
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
[danvet: Wrap paramters correctly in the macro and remove spurious
space checkpatch noticed.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

With this bit enabled, HW changes the color when compressing frames for
debug purposes.

ALthough the simple way to enable a single bit is over intel_reg_write,
this value is overwriten on next update_fbc so depending on the workload
it is not possible to set this bit with intel-gpu-tools. So this patch
introduces a persistent way to enable false color over debugfs.

v2: Use DEFINE_SIMPLE_ATTRIBUTE as Daniel suggested
v3: (Ville) only do false color for IVB+ since according to spec bit is
    MBZ before IVB.
v4: We don't have FBC on valleyview nor on cherryview (Ben)
v5: s/!HAS_PCH_SPLIT/!HAS_FBC (Ville)

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Signed-off-by: NSonika Jindal <sonika.jindal@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This was fumbled while trying to use the cached min/min/rpe values in
the vlv debugfs code.

    This is a regression from

    commit 03af2045
    Author: Ville Syrjälä <ville.syrjala@linux.intel.com>
    Date:   Sat Jun 28 02:03:53 2014 +0300

    drm/i915: Use the cached min/min/rpe values in the vlv debugfs code
Signed-off-by: NDeepak S <deepak.s@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Now that we use the runtime IRQ enable/disable functions in our suspend
path, we can simply check the pm._irqs_disabled flag everywhere.  So
rename it to catch the users, and add an inline for it to make the
checks clear everywhere.
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Add busy_frontbuffer_bits and locking.
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Trying to fish that one out through looping is a bit a locking
nightmare. So just set it and use it in the work struct.

v2:
- Don't Oops in psr_work, spotted by Rodrigo.
- Fix compile warning.
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

use the mst helper code to dump the topology in debugfs.

v0.2: drop is_mst check - as we want to dump other info
Reviewed-by: NTodd Previte <tprevite@gmail.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

DP MST will need connectors that aren't connected to specific
encoders, add some checks in advance to avoid oopses.
Reviewed-by: NTodd Previte <tprevite@gmail.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

No need to re-read the hardware rps fuses when we already have all the
values tucked away in dev_priv->rps.
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>

Still tacked onto the side, but slowly getting there.

v2: Don't forget the debugfs file.

v3 (from Paulo): Don't forget to check the power domains.
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

And get/put it when needed. The special thing about this commit is
that it will now return false in ibx_pch_dpll_get_hw_state() in case
the power domain is not enabled. This will fix some WARNs we have when
we run pm_rpm on SNB.

Testcase: igt/pm_rpm
Bugzilla:https://bugs.freedesktop.org/show_bug.cgi?id=80463Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Otherwise we will print some WARNs when we read registers and the
machine is suspended.

Testcase: igt/pm_rpm/debugfs-read
Cc: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

CHV hard hangs on reading on 0x11100

References: https://bugs.freedesktop.org/show_bug.cgi?id=80893Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

CHV hard hangs on reading on 0x112f4.

References: https://bugs.freedesktop.org/show_bug.cgi?id=80893Suggested-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

CHV hard hangs on reading these registers. As these have not
been used since cantiga & ilk, remove the debugfs entry.

References: https://bugs.freedesktop.org/show_bug.cgi?id=80893Suggested-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

CHV hard hangs on reading these registers. As these have not
been used since cantiga & ilk, remove the debugfs entry.

References: https://bugs.freedesktop.org/show_bug.cgi?id=80893Suggested-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This is an Execlists preparatory patch, since they make context ID become an
overloaded term:

- In the software, it was used to distinguish which context userspace was
  trying to use.
- In the BSpec, the term is used to describe the 20-bits long field the
  hardware uses to it to discriminate the contexts that are submitted to
  the ELSP and inform the driver about their current status (via Context
  Switch Interrupts and Context Status Buffers).

Initially, I tried to make the different meanings converge, but it proved
impossible:

- The software ctx->id is per-filp, while the hardware one needs to be
  globally unique.
- Also, we multiplex several backing states objects per intel_context,
  and all of them need unique HW IDs.
- I tried adding a per-filp ID and then composing the HW context ID as:
  ctx->id + file_priv->id + ring->id, but the fact that the hardware only
  uses 20-bits means we have to artificially limit the number of filps or
  contexts the userspace can create.

The ctx->user_handle renaming bits are done with this Cocci patch (plus
manual frobbing of the struct declaration):

    @@
    struct intel_context c;
    @@
    - (c).id
    + c.user_handle

    @@
    struct intel_context *c;
    @@
    - (c)->id
    + c->user_handle

Also, while we are at it, s/DEFAULT_CONTEXT_ID/DEFAULT_CONTEXT_HANDLE and
change the type to unsigned 32 bits.

v2: s/handle/user_handle and change the type to uint32_t as suggested by
Chris Wilson.

Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org> (v1)
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We have already advanced that Logical Ring Contexts have their own kind
of backing objects, but everything will be better explained in the Execlists
series. For now, suffice it to say that the current backing object is only
ever used with the render ring, so we're making this fact more explicit
(which is a good reason on its own).

As for the is_initialized flag, we only use to signify that the render state
has been initialized (a.k.a. golden context, a.k.a. null context). It doesn't
mean anything for the other engines, so make that distinction obvious.

Done with the following Coccinelle patch (plus manual frobbing of the struct):

    @@
    struct intel_context c;
    @@
    - (c).obj
    + c.legacy_hw_ctx.rcs_state

    @@
    struct intel_context *c;
    @@
    - (c)->obj
    + c->legacy_hw_ctx.rcs_state

    @@
    struct intel_context c;
    @@
    - (c).is_initialized
    + c.legacy_hw_ctx.initialized

    @@
    struct intel_context *c;
    @@
    - (c)->is_initialized
    + c->legacy_hw_ctx.initialized

This Execlists prep-work patch has been suggested by Chris Wilson and Daniel
Vetter separately.

Initially, it was two separate patches:
drm/i915: Rename ctx->obj to ctx->rcs_state
drm/i915: Make it obvious that ctx->id is merely a user handle
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
[danvet: s/id/is_initialized/ to fix the subject and resolve a
conflict in i915_gem_context_reset. Also introduce a new lctx local
variable to avoid overtly long lines.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Simple debugfs file to display the current state of semaphores. This is
useful if you want to see the state without hanging the GPU.

NOTE: This patch is optional to the series.

NOTE2: Like the GPU error state collection, the reads are currently
incoherent.

v2 (Rodrigo): * Iterate only on active rings.
   	      * s/ring_buffer/engine_cs.
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The always-on power well pixel path on haswell is routed such that it
bypasses the panel fitter when we use is. Which means the pfit CRC
source won't work in that configuration.

Add a new disallow-bypass flags to the pfit pipe config state and set
it when we want to use the pf CRC. Results in a bit of flicker, but
should get the job done. We'll also undo do it afterwards to make sure
other tests arent' negatively affected.

Totally untested due to lack of hsw laptops around here.

v2: s/disallow_bypass/force_power_well_on/ to avoid a double negative
(Damien).

v3: force_thru because roadsigns.

v4: Don't forget the power wells! Also note that until the runtime pm
for DPMS series is fully merged the simple disable/enable trick won't
work since the ->crtc_mode_set callback is still required to do nasty
things. This stuff is tricky, but I think by both fixing up
get_crtc_power_domains and the debugfs wa code we should always
grab/drop the additional power well correctly.

v5: Wrap in () as suggested by Damien to avoid setting reserved values
for the edp transcoder path on bdw+

References: https://bugs.freedesktop.org/show_bug.cgi?id=72864
Cc: Damien Lespiau <damien.lespiau@intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Tested-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

As pointed out before we don't have a reliable way to read back ips
status on BDW without the risk to disable it when reading.
However now we are pretending that IPS on BDW is always on and getting
people confused about it.

So this patch allows people to know if ips was ever attempted to be enabled.
Even if the current status is impossible to be ascertain.

v2: (spotted by Paulo):
     * A version that at least compiles
     * with more clear messages
     * let Cheryview on the safe side until we aren't sure that checking ips
       state on ips won't disable it.

Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Inlcude the pipe-size and cursor-size in debugfs.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

Fixes an issue whereby we may race with the table updates (before the
core takes the struct_mutex) and so risk dereferencing a stale pointer in
the iterator for /debugfs/.../i915_gem_objects. For example,

[ 1524.757545] BUG: unable to handle kernel paging request at f53af748
[ 1524.757572] IP: [<c1406982>] per_file_stats+0x12/0x100
[ 1524.757599] *pdpt = 0000000001b13001 *pde = 00000000379fb067 *pte = 80000000353af060
[ 1524.757621] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC
[ 1524.757637] Modules linked in: ctr ccm arc4 ath9k ath9k_common ath9k_hw ath snd_hda_codec_conexant mac80211 snd_hda_codec_generic snd_hda_intel snd_hda_controller snd_hda_codec bnep snd_hwdep rfcomm snd_pcm gpio_ich dell_wmi sparse_keymap snd_seq_midi hid_multitouch uvcvideo snd_seq_midi_event dell_laptop snd_rawmidi dcdbas snd_seq videobuf2_vmalloc videobuf2_memops videobuf2_core usbhid videodev snd_seq_device coretemp snd_timer hid joydev kvm_intel cfg80211 ath3k kvm btusb bluetooth serio_raw snd microcode soundcore lpc_ich wmi mac_hid parport_pc ppdev lp parport psmouse ahci libahci
[ 1524.757825] CPU: 3 PID: 1911 Comm: intel-gpu-overl Tainted: G        W  OE 3.15.0-rc3+ #96
[ 1524.757840] Hardware name: Dell Inc. Inspiron 1090/Inspiron 1090, BIOS A06 08/23/2011
[ 1524.757855] task: f52f36c0 ti: f4cbc000 task.ti: f4cbc000
[ 1524.757869] EIP: 0060:[<c1406982>] EFLAGS: 00210202 CPU: 3
[ 1524.757884] EIP is at per_file_stats+0x12/0x100
[ 1524.757896] EAX: 0000002d EBX: 00000000 ECX: f4cbdefc EDX: f53af700
[ 1524.757909] ESI: c1406970 EDI: f53af700 EBP: f4cbde6c ESP: f4cbde5c
[ 1524.757922]  DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
[ 1524.757934] CR0: 80050033 CR2: f53af748 CR3: 356af000 CR4: 000007f0
[ 1524.757945] Stack:
[ 1524.757957]  f4cbdefc 00000000 c1406970 f53af700 f4cbdea8 c12e5f15 f4cbdefc c1406970
[ 1524.757993]  0000ffff f4cbde90 0000002d f5dc5cd0 e4e80438 c1181d59 f4cbded8 f4d89900
[ 1524.758027]  f5631b40 e5131074 c1903f37 f4cbdf28 c14068e6 f52648a0 c1927748 c1903f37
[ 1524.758062] Call Trace:
[ 1524.758084]  [<c1406970>] ? i915_gem_object_info+0x510/0x510
[ 1524.758106]  [<c12e5f15>] idr_for_each+0xa5/0x100
[ 1524.758126]  [<c1406970>] ? i915_gem_object_info+0x510/0x510
[ 1524.758148]  [<c1181d59>] ? seq_vprintf+0x29/0x50
[ 1524.758168]  [<c14068e6>] i915_gem_object_info+0x486/0x510
[ 1524.758189]  [<c11823a6>] seq_read+0xd6/0x380
[ 1524.758208]  [<c116d11d>] ? final_putname+0x1d/0x40
[ 1524.758227]  [<c11822d0>] ? seq_hlist_next_percpu+0x90/0x90
[ 1524.758246]  [<c1163e52>] vfs_read+0x82/0x150
[ 1524.758265]  [<c11645d6>] SyS_read+0x46/0x90
[ 1524.758285]  [<c16b8d8c>] sysenter_do_call+0x12/0x22
[ 1524.758298] Code: f5 8f 2a 00 83 c4 6c 31 c0 5b 5e 5f 5d c3 8d 74 26 00 8d bc 27 00 00 00 00 55 89 e5 57 56 53 83 ec 04 3e 8d 74 26 00 83 41 04 01 <8b> 42 48 01 41 08 8b 42 4c 89 d7 85 c0 75 07 8b 42 60 85 c0 74
[ 1524.758461] EIP: [<c1406982>] per_file_stats+0x12/0x100 SS:ESP 0068:f4cbde5c
[ 1524.758485] CR2: 00000000f53af748
Reported-by: NSam Jansen <sam.jansen@starleaf.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Sam Jansen <sam.jansen@starleaf.com>
Cc: stable@vger.kernel.org
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

Can be useful to figure out imbalances and bugs in the frontbuffer
tracking.
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We could walk of a bad list otherwise when someone concurrently
unbinds stuff for fun.

I've suspected this as the root-cause behind seemingly inconsistent
state, but alas it's not.
Acked-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Now that the primary plane can be disabled independently of the CRTC,
the debugfs code needs to be updated to recognize when the primary plane
is disabled and not try to return information about the primary plane's
framebuffer.

This change prevents a NULL dereference when reading i915_display_info
with a disabled primary plane.

v2: Replace a seq_printf() with seq_puts() (suggested by Damien)
Signed-off-by: NMatt Roper <matthew.d.roper@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Now we have the active/inactive state for exit and this actually changes the
HW enable bit the status was a bit confusing for users. So let's provide
more info.
Reviewed-by: NVijay Purushothaman <vijay.a.purushothaman@intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Add Broadwell support to i915_frequency_info
and extend i915_max|min_freq_get|set to (gen >= 6).

v2: generalized support for i915_max|min_freq_get|set (Daniel).
Signed-off-by: NTom O'Rourke <Tom.O'Rourke@intel.com>
Reviewed-by: NJeff McGee <jeff.mcgee@intel.com>
[danvet: Fix checkpatch fail.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Otherwise we incur an unsightly WARNING. The mutex locking is a bit
overkill, but it curbs races and eventially we might grow a locking
check in the vblank wait code to make sure the right crtc lock is
held.

This is fallout from

commit 93937071
Author:     Jesse Barnes <jbarnes@virtuousgeek.org>
AuthorDate: Fri Apr 4 16:12:09 2014 -0700

    drm/i915: warn when a vblank wait times out

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=79612Tested-by: NGuo Jinxian <jinxianx.guo@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
[danvet: Rebase on top of drm core ww locking changes.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>