Re: [PATCH] Revert "drm/i915: Performed deferred clflush inside set-cache-level"

[Sudip Mukherjee <sudipm.mukherjee@gmail.com>]

On Wed, Apr 01, 2015 at 10:01:50AM +0530, Sudip Mukherjee wrote:
> On Tue, Mar 31, 2015 at 04:35:49PM +0100, Chris Wilson wrote:
> > On Tue, Mar 31, 2015 at 08:40:12PM +0530, Sudip Mukherjee wrote:
> > > This reverts commit <0f71979ab7fbd0c71c41c2798de3d33937915434>.
> > > 
> > > my display was getting garbled for a moment very frequently. it looked
> > > like when the screen was getting refreshed then something was going
> > > wrong.
> > > git bisect gave this as the first bad commit, and after reverting it
> > > now display is not having that problem.
> > 
> > Hmm, I fear you would be just papering over a bug. Could you please file
> > a bug on bugs.freedesktop.org so that we can root cause this?
> > -Chris
> filed at https://bugs.freedesktop.org/show_bug.cgi?id=89857
> 
> since this patch workes perfectly for me, i guess i need to apply it to
> every new release till you are able to root cause and fix it.

I am having the same problem with v4.0 also. Though I guess there is
some improvement as now the problem is not appearing as frequently as
it used to be.
And reverting the patch again completely removed the problem.

regards
sudip