1. 03 9月, 2014 4 次提交
  2. 18 8月, 2014 1 次提交
    • I
      drm/i915: fix HPD IRQ reenable work cancelation · 6323751d
      Imre Deak 提交于
      Atm, the HPD IRQ reenable timer can get rearmed right after it's
      canceled. Also to access the HPD IRQ mask registers we need to wake up
      the HW.
      
      Solve both issues by converting the reenable timer to a delayed work and
      grabbing a runtime PM reference in the work. By this we can also forgo
      canceling the timer during runtime suspend, since the only important
      thing there is that the HW is awake when we write the registers and
      that's ensured by the RPM ref. So do the cancelation only during driver
      unload time; this is also a requirement for an upcoming patch where we
      want to cancel all HPD related works only during system suspend and
      driver unload time, but not during runtime suspend.
      
      Note that there is still a race between the HPD IRQ reenable work and
      drm_irq_uninstall() during driver unload, where the work can reenable
      the HPD IRQs disabled by drm_irq_uninstall(). This isn't a problem since
      the HPD IRQs will still be effectively masked by the first level
      interrupt mask.
      
      v2-3:
      - unchanged
      v4:
      - use proper API for changing the expiration time for an already pending
        delayed work (Jani)
      Signed-off-by: NImre Deak <imre.deak@intel.com>
      Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> (v2)
      Cc: stable@vger.kernel.org (3.16+)
      Signed-off-by: NJani Nikula <jani.nikula@intel.com>
      6323751d
  3. 15 8月, 2014 1 次提交
    • T
      drm/i915/bdw: Handle context switch events · e981e7b1
      Thomas Daniel 提交于
      Handle all context status events in the context status buffer on every
      context switch interrupt. We only remove work from the execlist queue
      after a context status buffer reports that it has completed and we only
      attempt to schedule new contexts on interrupt when a previously submitted
      context completes (unless no contexts are queued, which means the GPU is
      free).
      
      We canot call intel_runtime_pm_get() in an interrupt (or with a spinlock
      grabbed, FWIW), because it might sleep, which is not a nice thing to do.
      Instead, do the runtime_pm get/put together with the create/destroy request,
      and handle the forcewake get/put directly.
      Signed-off-by: NThomas Daniel <thomas.daniel@intel.com>
      
      v2: Unreferencing the context when we are freeing the request might free
      the backing bo, which requires the struct_mutex to be grabbed, so defer
      unreferencing and freeing to a bottom half.
      
      v3:
      - Ack the interrupt inmediately, before trying to handle it (fix for
      missing interrupts by Bob Beckett <robert.beckett@intel.com>).
      - Update the Context Status Buffer Read Pointer, just in case (spotted
      by Damien Lespiau).
      
      v4: New namespace and multiple rebase changes.
      
      v5: Squash with "drm/i915/bdw: Do not call intel_runtime_pm_get() in an
      interrupt", as suggested by Daniel.
      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>
      e981e7b1
  4. 12 8月, 2014 2 次提交
  5. 09 8月, 2014 1 次提交
  6. 08 8月, 2014 3 次提交
    • D
      drm/i915: Introduce a for_each_intel_encoder() macro · b2784e15
      Damien Lespiau 提交于
      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>
      b2784e15
    • P
      d rm/i915: freeze display before the interrupts and GT · 06ffc778
      Paulo Zanoni 提交于
      Since we started using intel_runtime_pm_disable_interrupts() at normal
      (non-runtime) suspend/resume, we had to remove a WARN from
      ironlake_disable_display_irq to avoid a case where we were doing the
      correct thing and the WARN was not really needed. The problem is that
      the WARN was useful in other cases, and its removal can hide some bugs
      that we would catch automatically.
      
      To be able to add back the WARN, we have to call intel_crtc_control()
      before interrupts are disabled, which is what this patch currently
      does.
      
      Also notice that Ville's patch from the Watermarks series "drm/i915:
      Leave interrupts enabled while disabling crtcs during suspend" also
      did a change that's equivalent to the one we're doing on this patch,
      with the exception that its original patch, when applied to the
      current tree, procduces a WARN.
      
      Related commits:
      
      commit daa390e5ee45cc051d6bf37b296901f2f92b002d
      Author: Jesse Barnes <jbarnes@virtuousgeek.org>
          drm/i915: don't warn if IRQs are disabled when shutting down display IRQs
      
      commit e11aa362
      Author: Jesse Barnes <jbarnes@virtuousgeek.org>
          drm/i915: use runtime irq suspend/resume in freeze/thaw
      
      Note that the function part of this patch has already been done in
      
      commit 0e32b39c
      Author: Dave Airlie <airlied@redhat.com>
      Date:   Fri May 2 14:02:48 2014 +1000
      
          drm/i915: add DP 1.2 MST support (v0.7)
      
      with the fixup
      
      commit 09b64267
      Author: Dave Airlie <airlied@redhat.com>
      Date:   Wed Jul 23 14:25:24 2014 +1000
      
          drm/i915: don't suspend gt until after we disable irqs and display (v2)
      
      so all that's left from Paulo's patch is reinstating the WARNING.
      
      Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
      Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
      Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
      Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
      [danvet: Explain conflict resolution with Dave's DP MST patches with a
      note in the commit message.]
      Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      06ffc778
    • V
      drm/i915: Kill intel_crtc->vbl_wait · 210871b6
      Ville Syrjälä 提交于
      Share the waitqueue that drm_irq uses when performing the vblank evade
      trick for atomic pipe updates.
      
      v2: Keep intel_pipe_handle_vblank() (Chris)
      Suggested-by: NDaniel Vetter <daniel@ffwll.ch>
      Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
      Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      210871b6
  7. 07 8月, 2014 1 次提交
  8. 23 7月, 2014 7 次提交
  9. 22 7月, 2014 2 次提交
    • D
      drm/i915: add DP 1.2 MST support (v0.7) · 0e32b39c
      Dave Airlie 提交于
      This adds DP 1.2 MST support on Haswell systems.
      
      Notes:
      a) this reworks irq handling for DP MST ports, so that we can
      avoid the mode config locking in the current hpd handlers, as
      we need to process up/down msgs at a better time.
      
      Changes since v0.1:
      use PORT_PCH_HOTPLUG to detect short vs long pulses
      add a workqueue to deal with digital events as they can get blocked on the
      main workqueue beyong mode_config mutex
      fix a bunch of modeset checker warnings
      acks irqs in the driver
      cleanup the MST encoders
      
      Changes since v0.2:
      check irq status again in work handler
      move around bring up and tear down to fix DPMS on/off
      use path properties.
      
      Changes since v0.3:
      updates for mst apis
      more state checker fixes
      irq handling improvements
      fbcon handling support
      improved reference counting of link - fixes redocking.
      
      Changes since v0.4:
      handle gpu reset hpd reinit without oopsing
      check link status on HPD irqs
      fix suspend/resume
      
      Changes since v0.5:
      use proper functions to get max link/lane counts
      fix another checker backtrace - due to connectors disappearing.
      set output type in more places fro, unknown->displayport
      don't talk to devices if no HPD asserted
      check mst on short irqs only
      check link status properly
      rebase onto prepping irq changes.
      drop unsued force_act
      
      Changes since v0.6:
      cleanup unused struct entry.
      
      [airlied: fix some sparse warnings].
      Reviewed-by: NTodd Previte <tprevite@gmail.com>
      Signed-off-by: NDave Airlie <airlied@redhat.com>
      0e32b39c
    • C
      drm/i915: Reorder the semaphore deadlock check, again · a0d036b0
      Chris Wilson 提交于
      commit 4be17381
      Author: Chris Wilson <chris@chris-wilson.co.uk>
      Date:   Fri Jun 6 10:22:29 2014 +0100
      
          drm/i915: Reorder semaphore deadlock check
      
      did the majority of the work, but it missed one crucial detail:
      
      The check for the unkickable deadlock on this ring must come after the
      check whether the ring that we are waiting on has already passed its
      target seqno.
      
      Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=80709Tested-by: NStefan Huber <shuber@sthu.org>
      Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
      Cc: Mika Kuoppala <mika.kuoppala@intel.com>
      Cc: Jani Nikula <jani.nikula@intel.com>
      Cc: stable@vger.kernel.org
      Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      a0d036b0
  10. 21 7月, 2014 1 次提交
  11. 12 7月, 2014 1 次提交
  12. 11 7月, 2014 1 次提交
  13. 09 7月, 2014 1 次提交
  14. 08 7月, 2014 2 次提交
    • D
      drm/fb-helper: Fix hpd vs. initial config races · 50c3dc97
      Daniel Vetter 提交于
      Some drivers need to be able to have a perfect race-free fbcon setup.
      Current drivers only enable hotplug processing after the call to
      drm_fb_helper_initial_config which leaves a tiny but important race.
      
      This race is especially noticable on embedded platforms where the
      driver itself enables the voltage for the hdmi output, since only then
      will monitors (after a bit of delay, as usual) respond by asserting
      the hpd pin.
      
      Most of the infrastructure is already there with the split-out
      drm_fb_helper_init. And drm_fb_helper_initial_config already has all
      the required locking to handle concurrent hpd events since
      
      commit 53f1904b
      Author: Daniel Vetter <daniel.vetter@ffwll.ch>
      Date:   Thu Mar 20 14:26:35 2014 +0100
      
          drm/fb-helper: improve drm_fb_helper_initial_config locking
      
      The only missing bit is making drm_fb_helper_hotplug_event save
      against concurrent calls of drm_fb_helper_initial_config. The only
      unprotected bit is the check for fb_helper->fb.
      
      With that drivers can first initialize the fb helper, then enabel
      hotplug processing and then set up the initial config all in a
      completely race-free manner. Update kerneldoc and convert i915 as a
      proof of concept.
      
      Feature requested by Thierry since his tegra driver atm reliably boots
      slowly enough to misses the hotplug event for an external hdmi screen,
      but also reliably boots to quickly for the hpd pin to be asserted when
      the fb helper calls into the hdmi ->detect function.
      
      Cc: Thierry Reding <treding@nvidia.com>
      Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      Signed-off-by: NThierry Reding <treding@nvidia.com>
      Signed-off-by: NDave Airlie <airlied@redhat.com>
      50c3dc97
    • R
      drm/i915: Implement MI decode for gen8 · a6cdb93a
      Rodrigo Vivi 提交于
      Ipehr just carries Dword 0 and on Gen 8, offsets are located
      on Dword 2 and 3 of MI_SEMAPHORE_WAIT.
      
      This implementation was based on Ben's work and on Ville's suggestion for Ben
      
      Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
      Cc: Ben Widawsky <ben@bwidawsk.net>
      Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
      Reviewed-by: NBen Widawsky <ben@bwidawsk.net>
      [danvet: Fixup format string.]
      Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      a6cdb93a
  15. 07 7月, 2014 1 次提交
    • D
      drm/i915: rework digital port IRQ handling (v2) · 13cf5504
      Dave Airlie 提交于
      The digital ports from Ironlake and up have the ability to distinguish
      between long and short HPD pulses. Displayport 1.1 only uses the short
      form to request link retraining usually, so we haven't really needed
      support for it until now.
      
      However with DP 1.2 MST we need to handle the short irqs on their
      own outside the modesetting locking the long hpd's involve. This
      patch adds the framework to distinguish between short/long to the
      current code base, to lay the basis for future DP 1.2 MST work.
      
      This should mean we get better bisectability in case of regression
      due to the new irq handling.
      
      v2: add GM45 support (untested, due to lack of hw)
      Signed-off-by: NDave Airlie <airlied@redhat.com>
      Reviewed-by: NTodd Previte <tprevite@gmail.com>
      [danvet: Fix conflicts in i915_irq.c with Oscar Mateo's irq handling
      race fixes and a trivial one in intel_drv.h with the psr code.]
      Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      13cf5504
  16. 18 6月, 2014 4 次提交
    • O
      drm/i915/chv: Ack interrupts before handling them (CHV) · 27b6c122
      Oscar Mateo 提交于
      Otherwise, we might receive a new interrupt before we have time to
      ack the first one, eventually missing it.
      
      Without an atomic XCHG operation with mmio space, this patch merely
      reduces the window in which we can miss an interrupt (especially when
      you consider how heavyweight the I915_READ/I915_WRITE operations are).
      
      Notice that, before clearing a port-sourced interrupt in the IIR, the
      corresponding interrupt source status in the PORT_HOTPLUG_STAT must be
      cleared.
      
      Spotted by Bob Beckett <robert.beckett@intel.com>.
      
      v2:
      - Add warning to commit message and comments to the code as per Chris
        Wilson's request.
      - Imre Deak pointed out that the pipe underrun flag might not be signaled
        in IIR, so do not make valleyview_pipestat_irq_handler depend on it.
      
      v3: Improve the source code comment.
      Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
      Reviewed-by: NImre Deak <imre.deak@intel.com>
      Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      27b6c122
    • O
      drm/i915/bdw: Ack interrupts before handling them (GEN8) · 38cc46d7
      Oscar Mateo 提交于
      Otherwise, we might receive a new interrupt before we have time to
      ack the first one, eventually missing it.
      
      The right order should be:
      
      1 - Disable Master Interrupt Control.
      2 - Find the category of interrupt that is pending.
      3 - Find the source(s) of the interrupt and clear the Interrupt Identity bits (IIR)
      4 - Process the interrupt(s) that had bits set in the IIRs.
      5 - Re-enable Master Interrupt Control.
      
      Without an atomic XCHG operation with mmio space, the above merely reduces the window
      in which we can miss an interrupt (especially when you consider how heavyweight the
      I915_READ/I915_WRITE operations are).
      
      Spotted by Bob Beckett <robert.beckett@intel.com>.
      
      v2: Add warning to commit message and comments to the code as per Chris Wilson's request.
      
      v3: Improve the source code comment.
      Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
      Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      38cc46d7
    • O
      drm/i915/vlv: Ack interrupts before handling them (VLV) · 3ff60f89
      Oscar Mateo 提交于
      Otherwise, we might receive a new interrupt before we have time to
      ack the first one, eventually missing it.
      
      Without an atomic XCHG operation with mmio space, this patch merely
      reduces the window in which we can miss an interrupt (especially when
      you consider how heavyweight the I915_READ/I915_WRITE operations are).
      
      Notice that, before clearing a port-sourced interrupt in the IIR, the
      corresponding interrupt source status in the PORT_HOTPLUG_STAT must be
      cleared.
      
      Spotted by Bob Beckett <robert.beckett@intel.com>.
      
      v2:
      - Reorder the IIR clearing to reduce the window even further.
      - Add warning to commit message and comments to the code as per Chris
        Wilson's request.
      - Imre Deak pointed out that the pipe underrun flag might not be signaled
        in IIR, so do not make valleyview_pipestat_irq_handler depend on it.
      
      v3: Improve the source code comment.
      Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
      Reviewed-by: NImre Deak <imre.deak@intel.com>
      Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      3ff60f89
    • O
      drm/i915: Ack interrupts before handling them (GEN5 - GEN7) · 72c90f62
      Oscar Mateo 提交于
      Otherwise, we might receive a new interrupt before we have time to ack the first
      one, eventually missing it.
      
      According to BSPec, the right order should be:
      
      1 - Disable Master Interrupt Control.
      2 - Find the source(s) of the interrupt.
      3 - Clear the Interrupt Identity bits (IIR).
      4 - Process the interrupt(s) that had bits set in the IIRs.
      5 - Re-enable Master Interrupt Control.
      
      Without an atomic XCHG operation with mmio space, the above merely reduces the window
      in which we can miss an interrupt (especially when you consider how heavyweight the
      I915_READ/I915_WRITE operations are).
      
      We maintain the "disable SDE interrupts when handling" hack since apparently it works.
      
      Spotted by Bob Beckett <robert.beckett@intel.com>.
      
      v2: Add warning to commit message and comments to the code as per Chris Wilson's request.
      v3: Improve the source comments.
      Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
      Reviewed-by: NImre Deak <imre.deak@intel.com>
      Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      72c90f62
  17. 17 6月, 2014 1 次提交
    • S
      drm/i915: Replaced Blitter ring based flips with MMIO flips · 84c33a64
      Sourab Gupta 提交于
      This patch enables the framework for using MMIO based flip calls,
      in contrast with the CS based flip calls which are being used currently.
      
      MMIO based flip calls can be enabled on architectures where
      Render and Blitter engines reside in different power wells. The
      decision to use MMIO flips can be made based on workloads to give
      100% residency for Media power well.
      
      v2: The MMIO flips now use the interrupt driven mechanism for issuing the
      flips when target seqno is reached. (Incorporating Ville's idea)
      
      v3: Rebasing on latest code. Code restructuring after incorporating
      Damien's comments
      
      v4: Addressing Ville's review comments
          -general cleanup
          -updating only base addr instead of calling update_primary_plane
          -extending patch for gen5+ platforms
      
      v5: Addressed Ville's review comments
          -Making mmio flip vs cs flip selection based on module parameter
          -Adding check for DRIVER_MODESET feature in notify_ring before calling
           notify mmio flip.
          -Other changes mostly in function arguments
      
      v6: -Having a seperate function to check condition for using mmio flips (Ville)
          -propogating error code from i915_gem_check_olr (Ville)
      
      v7: -Adding __must_check with i915_gem_check_olr (Chris)
          -Renaming mmio_flip_data to mmio_flip (Chris)
          -Rebasing on latest nightly
      
      v8: -Rebasing on latest code
          -squash 3rd patch in series(mmio setbase vs page flip race) with this patch
          -Added new tiling mode update in intel_do_mmio_flip (Chris)
      
      v9: -check for obj->last_write_seqno being 0 instead of obj->ring being NULL in
      intel_postpone_flip, as this is a more restrictive condition (Chris)
      
      v10: -Applied Chris's suggestions for squashing patches 2,3 into this patch.
      These patches make the selection of CS vs MMIO flip at the page flip time, and
      make the module parameter for using mmio flips as tristate, the states being
      'force CS flips', 'force mmio flips', 'driver discretion'.
      Changed the logic for driver discretion (Chris)
      
      v11: Minor code cleanup(better readability, fixing whitespace errors, using
      lockdep to check mutex locked status in postpone_flip, removal of __must_check
      in function definition) (Chris)
      Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
      Signed-off-by: NSourab Gupta <sourab.gupta@intel.com>
      Signed-off-by: NAkash Goel <akash.goel@intel.com>
      Tested-by: Chris Wilson <chris@chris-wilson.co.uk> # snb, ivb
      [danvet: Fix up parameter alignement checkpatch spotted.]
      Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      84c33a64
  18. 11 6月, 2014 2 次提交
  19. 05 6月, 2014 4 次提交
    • V
      drm/i915: Set AGPBUSY# bit in init_clock_gating · 12fabbcb
      Ville Syrjälä 提交于
      I don't see why we wouldn't want interrupts to wake up the CPU from C3
      always, so just set the AGPBUSY# bit in gen3_init_clock_gating().
      Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
      Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
      Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      12fabbcb
    • D
      drm/i915: Extract gen8_gt_irq_reset · d6e3cca3
      Daniel Vetter 提交于
      Fallout from an intermediate patch revision that I deemed worth saving.
      
      Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
      Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
      Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      d6e3cca3
    • D
      drm/i915: Inline ilk/gen8_irq_reset · 723761b8
      Daniel Vetter 提交于
      No point in having this indirection.
      Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
      Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      723761b8
    • D
      drm/i915: Fix up fifo underrun tracking, take N · 2ae2a50c
      Daniel Vetter 提交于
      So apparently this is tricky.
      
      We need to consider:
      - We start out with all the hw enabling bits disabled, both the
        individual fifo underrun interrupts and the shared display error
        interrupts masked. Otherwise if the bios config is broken we'll blow
        up with a NULL deref in our interrupt handler since the crtc
        structures aren't set up yet at driver load time.
      - On gmch we need to mask fifo underruns on the sw side, so always
        need to set that in sanitize_crtc for those platforms.
      - On other platforms we try to set the sw tracking so that it reflects
        the real state. But since a few platforms have shared bits we must
        _not_ disable fifo underrun reporting. Otherwise we'll never enable
        the shared error interrupt.
      
      This is the state before out patch, but unfortunately this is not good
      enough. But after a suspend resume operation this is broken:
      1. We don't enable the hw interrupts since the same code runs on
      resume as on driver load.
      2. The fifo underrun state adjustments we do in sanitize_crtc doesn't
      fire on resume since (except for hilarious firmware) all pipes are off
      at that point. But they also don't hurt since the subsequent crtc
      enabling due to force_restore will enable fifo underruns.
      
      Which means when we enable fifo underrun reporting we notice that the
      per-crtc state is already correct and short-circuit everthing out. And
      the interrupt doesn't get enabled.
      
      A similar problem would happen if the bios doesn't light up anything
      when the driver loads. Which is exactly what happens when we reload
      the driver since our unload functions disables all outputs.
      
      Now we can't just rip out the short-circuit logic and unconditionally
      update the fifo underrun reporting interrupt masking: We have some
      checks for shared error interrupts to catch issues that happened when
      the shared error interrupt was disabled.
      
      The right fix is to push down this logic so that we can always update
      the hardware state, but only check for missed fifo underruns on a real
      enabled->disabled transition and ignore them when we're already
      disabled.
      
      On platforms with shared error interrupt the pipe CRC interrupts are
      grouped together with the fifo underrun reporting this fixes pipe CRC
      support after suspend and driver reloads.
      
      Testcase: igt/kms_pipe_crc_basic/suspend-*
      Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
      Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      2ae2a50c