Re: [PATCH v2] drm/i915: Flush untouched framebuffers before display on !llc

From: Chris Wilson
Date: Thu Jan 12 2017 - 17:38:20 EST


On Thu, Jan 12, 2017 at 04:24:50PM -0600, lkml@xxxxxxxxxxx wrote:
> On Thu, Jan 12, 2017 at 09:17:06PM +0000, Chris Wilson wrote:
> > On Mon, Jan 09, 2017 at 11:19:32AM +0000, Chris Wilson wrote:
> > > On a non-llc system, the objects are created with .cache_level =
> > > CACHE_NONE and so the transition to uncached for scanout is a no-op.
> > > However, if the object was never written to, it will still be in the CPU
> > > domain (having been zeroed out by shmemfs). Those cachelines need to be
> > > flushed prior to display.
> > >
> > > Reported-by: Vito Caputo
> > > Fixes: a6a7cc4b7db6 ("drm/i915: Always flush the dirty CPU cache when pinning the scanout")
> > > Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
> > > Cc: <drm-intel-fixes@xxxxxxxxxxxxxxxxxxxxx> # v4.10-rc1+
> >
> > Ping?
>
> This patch fixes the problem for me, in case that's what the ping's for.

Partly that, and trying to catch CI + reviewers.

> Out of curiosity the bug I reported described here be getting fixed in 4.10?
> https://lists.freedesktop.org/archives/dri-devel/2017-January/128405.html

It was fixed in the tree back in December, bit of a muddle to get that
particular patch into 4.10.
-Chris

--
Chris Wilson, Intel Open Source Technology Centre