[Bug 97965] [BSW] External HDMI monitor suddenly shows solid color when playing Youtube video at 1080p [fifo underrun]

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=97965

--- Comment #27 from Yu Kang Ku <ykku16dev2 at gmail.com> ---
Created attachment 127130
  --> https://bugs.freedesktop.org/attachment.cgi?id=127130&action=edit
Output of intel_watermark with trickle feed

(In reply to Ville Syrjala from comment #25, part 2)

> Another thing you could try is enable trickle feed. That shouldn't change
> much though as it's essentially just always forcing the watermarks to 8 or
> something like that. But worth a shot anyway I suppose:
> 
> --- a/drivers/gpu/drm/i915/intel_runtime_pm.c
> +++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
> @@ -1070,7 +1070,7 @@ static void vlv_init_display_clock_gating(struct
> drm_i915_private *dev_priv)
>         /*
>          * Disable trickle feed and enable pnd deadline calculation
>          */
> -       I915_WRITE(MI_ARB_VLV, MI_ARB_DISPLAY_TRICKLE_FEED_DISABLE);
> +       I915_WRITE(MI_ARB_VLV, 0);
>         I915_WRITE(CBR1_VLV, 0);
>  
>         WARN_ON(dev_priv->rawclk_freq == 0);

I repeated the dock-mode experiment, adding this trickle-feed change along with
the PM2-limit change.  The trickle-feed change did not help.  The problem is
still reproducible.  Attached is the output of intel_watermark showing that the
trickle change took effect.

-- 
You are receiving this mail because:
You are the QA Contact for the bug.
You are on the CC list for the bug.
You are the assignee for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/intel-gfx-bugs/attachments/20161007/2fb47683/attachment.html>