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            <b><a class="bz_bug_link 
          bz_status_NEEDINFO "
   title="NEEDINFO --- - [ivb] hang on pageflip"
   href="https://bugs.freedesktop.org/show_bug.cgi?id=74053#c6">Comment # 6</a>
              on <a class="bz_bug_link 
          bz_status_NEEDINFO "
   title="NEEDINFO --- - [ivb] hang on pageflip"
   href="https://bugs.freedesktop.org/show_bug.cgi?id=74053">bug 74053</a>
              from <span class="vcard"><a class="email" href="mailto:chris@chris-wilson.co.uk" title="Chris Wilson <chris@chris-wilson.co.uk>"> <span class="fn">Chris Wilson</span></a>
</span></b>
        <pre>One wicked theory I have is that the intoduction of the working SRM is breaking
the flips...

Can you please test:

diff --git a/drivers/gpu/drm/i915/intel_display.c
b/drivers/gpu/drm/i915/intel_display.c
index 5b7ce3f09681..de70260e50f3 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -8593,7 +8593,7 @@ static int intel_gen7_queue_flip(struct drm_device *dev,

        len = 4;
        if (ring->id == RCS)
-               len += 6;
+               len += 4;

        ret = intel_ring_begin(ring, len);
        if (ret)
@@ -8614,10 +8614,7 @@ static int intel_gen7_queue_flip(struct drm_device *dev,
                intel_ring_emit(ring, ~(DERRMR_PIPEA_PRI_FLIP_DONE |
                                        DERRMR_PIPEB_PRI_FLIP_DONE |
                                        DERRMR_PIPEC_PRI_FLIP_DONE));
-               intel_ring_emit(ring, MI_STORE_REGISTER_MEM(1) |
-                               MI_SRM_LRM_GLOBAL_GTT);
-               intel_ring_emit(ring, DERRMR);
-               intel_ring_emit(ring, ring->scratch.gtt_offset + 256);
+               intel_ring_emit(ring, MI_NOOP);
        }</pre>
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