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            <b><a class="bz_bug_link 
          bz_status_NEW "
   title="NEW - fullscreen flickering with google-chrome (youtube and not only)"
   href="https://bugs.freedesktop.org/show_bug.cgi?id=94987#c13">Comment # 13</a>
              on <a class="bz_bug_link 
          bz_status_NEW "
   title="NEW - fullscreen flickering with google-chrome (youtube and not only)"
   href="https://bugs.freedesktop.org/show_bug.cgi?id=94987">bug 94987</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>Drat. Best idea I had so far.

Likely no effect, but do please try:

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 6ce2c31..1b296e2 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -54,6 +54,9 @@ static bool cpu_cache_is_coherent(struct drm_device *dev,

 static bool cpu_write_needs_clflush(struct drm_i915_gem_object *obj)
 {
+       if (obj->base.write_domain == I915_GEM_DOMAIN_CPU)
+               return false;
+
        if (!cpu_cache_is_coherent(obj->base.dev, obj->cache_level))
                return true;

@@ -1080,7 +1083,6 @@ i915_gem_pwrite_ioctl(struct drm_device *dev, void *data,
         * perspective, requiring manual detiling by the client.
         */
        if (obj->tiling_mode == I915_TILING_NONE &&
-           obj->base.write_domain != I915_GEM_DOMAIN_CPU &&
            cpu_write_needs_clflush(obj)) {
                ret = i915_gem_gtt_pwrite_fast(dev, obj, args, file);
                /* Note that the gtt paths might fail with non-page-backed user
@@ -3926,10 +3928,8 @@ out:
         * object is now coherent at its new cache level (with respect
         * to the access domain).
         */
-       if (obj->cache_dirty &&
-           obj->base.write_domain != I915_GEM_DOMAIN_CPU &&
-           cpu_write_needs_clflush(obj)) {
-               if (i915_gem_clflush_object(obj, true))
+       if (cpu_write_needs_clflush(obj)) {
+               if (i915_gem_clflush_object(obj, obj->cache_dirty))
                        i915_gem_chipset_flush(obj->base.dev);
        }</pre>
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