Em Qui, 2016-06-09 às 11:58 -0400, Lyude escreveu:

From https://bugs.freedesktop.org/show_bug.cgi?id=96461 :

This was kind of a difficult bug to track down. If you're using a Haswell system running GNOME and you have fbc completely enabled and working, playing videos can result in video artifacts. Steps to reproduce:

• Run GNOME
• Ensure FBC is enabled and active
• Download a movie, I used the ogg version of Big Buck Bunny for this
• Run `gst-launch-1.0 filesrc location='some_movie.ogg' ! decodebin !

glimagesink` in a terminal

• Watch for about over a minute, you'll see small horizontal lines go

down the screen.

If you "dmesg | grep -i underrun", do you see anything (even if it doesn't happen during the moments of corruption)?

Does the problem still happen if you apply these patches?  - https://patchwork.freedesktop.org/patch/79567/  - https://patchwork.freedesktop.org/patch/80857/  - https://patchwork.freedesktop.org/patch/92634/

For the time being, disable FBC for Haswell by default.

In case we want to improve the commit message:

We also got reports from Steven Honeyman on openbox+roxterm, and from Stefan Richter.

Anyway, there's a regression that needs to be fixed, so:

Reviewed-by: Paulo Zanoni paulo.r.zanoni@intel.com

We can always try again later.

Signed-off-by: Lyude cpaul@redhat.com Cc: stable@vger.kernel.org

---

drivers/gpu/drm/i915/intel_fbc.c | 3 +--  1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_fbc.c b/drivers/gpu/drm/i915/intel_fbc.c index 0f0492f..28f4407 100644 --- a/drivers/gpu/drm/i915/intel_fbc.c +++ b/drivers/gpu/drm/i915/intel_fbc.c @@ -823,8 +823,7 @@ static bool intel_fbc_can_choose(struct intel_crtc *crtc)  {   struct drm_i915_private *dev_priv = crtc->base.dev-

...

dev_private;

struct intel_fbc *fbc = &dev_priv->fbc;

• bool enable_by_default = IS_HASWELL(dev_priv) ||

• 		 IS_BROADWELL(dev_priv);
  

• bool enable_by_default = IS_BROADWELL(dev_priv);

if (intel_vgpu_active(dev_priv->dev)) {   fbc->no_fbc_reason = "VGPU is active";