[Intel-gfx] [PATCH] drm/i915: Invariably invalidate before ctx switch

[Daniel Vetter]

On Thu, Apr 03, 2014 at 08:05:35AM +0100, Chris Wilson wrote:
> On Wed, Apr 02, 2014 at 10:30:23PM -0700, Ben Widawsky wrote:
> > We have been setting the bit which was originally BIOS dependent since:
> > commit f05bb0c7b624252a5e768287e340e8e45df96e42
> > Author: Chris Wilson <chris at chris-wilson.co.uk>
> > Date:   Sun Jan 20 16:33:32 2013 +0000
> > 
> >     drm/i915: GFX_MODE Flush TLB Invalidate Mode must be '1' for scanline waits
> > 
> > Therefore, we do not need to try to figure it out dynamically and we can
> > just always invalidate the TLBs.
> > 
> > It's a partial revert of:
> > commit 12b0286f49947a6cdc9285032d918466a8c3f5f9
> > Author: Ben Widawsky <ben at bwidawsk.net>
> > Date:   Mon Jun 4 14:42:50 2012 -0700
> > 
> >     drm/i915: possibly invalidate TLB before context switch
> > 
> > The original commit attempted to only invalidate when necessary
> > (very much a relic from the old days). Now, we can just always invalidate.
> > 
> > I guess the old TODO still exists. Since we seem to have abandoned ILK
> > contexts however, there isn't much point in even remembering.
> > 
> > Cc: Chris Wilson <chris at chris-wilson.co.uk>
> > Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
> 
> Seems reasonable, except in most cases (execbuffer) there will be
> a following cache-invalidate as part of the move-to-gpu.
> 
> Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>

Queued for -next, thanks for the patch.

> ILK ctx, never forget.

Iirc those patches still hang in there ;-)

Cheers, Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch