[Intel-gfx] [PATCH 00/10] drm-intel-collector - update

[Chris Wilson]

On Tue, Nov 11, 2014 at 02:16:32PM +0200, Ville Syrjälä wrote:
> On Tue, Nov 11, 2014 at 12:54:13PM +0100, Daniel Vetter wrote:
> > On Tue, Nov 11, 2014 at 10:22:11AM +0000, Chris Wilson wrote:
> > > On Tue, Nov 11, 2014 at 11:20:14AM +0100, Daniel Vetter wrote:
> > > > On Thu, Nov 06, 2014 at 09:57:29AM +0200, Ville Syrjälä wrote:
> > > > > On Tue, Nov 04, 2014 at 04:51:38AM -0800, Rodrigo Vivi wrote:
> > > > > > Patch     drm/i915: Make the physical object coherent with GTT - Reviewer:
> > > > > 
> > > > > Already has my r-b.
> > > > 
> > > > I still would like to see a little testcase here, e.g. a new mode to
> > > > kms_cursor_crc which uses gtt mmap uploads instead of pwrite.
> > > 
> > > But that doesn't block this patch, as the kernel already exposes and
> > > userspace already uses gtt mmap updates to the cursor. The patch just
> > > removes the barrier to do so using early chipsets as well.
> > 
> > Well yeah, but that existing code has piles of tests already to make sure
> > that gtt writes are somewhat coherent with pwrite, and another test that
> > pwrite is coherent with the actual cursor scanned out by hw.
> 
> Actually pwrite isn't coherent with scanout currently on LLC platforms
> if you do the pwrite when the bo already has cache_level==NONE but it's
> not yet pinned to the display. So seems our pwrite tests aren't entirely
> comprehensive currently if they don't hit this. I still haven't seen
> the fabled patch from Chris that would fix this.

This patch includes an unconditional clflush for phys writes (or at
least this patch should be that patch) which is what I thought we were
arguing about at the time.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre