[Intel-gfx] [PATCH] drm/i915: Click the ACTHD three times to go home

[Chris Wilson]

On Mon, Mar 27, 2017 at 02:30:08PM +0100, Chris Wilson wrote:
> On Mon, Mar 27, 2017 at 04:19:58PM +0300, Mika Kuoppala wrote:
> > Chris Wilson <chris at chris-wilson.co.uk> writes:
> > 
> > > On Mon, Mar 27, 2017 at 01:12:30PM +0300, Mika Kuoppala wrote:
> > >> Chris Wilson <chris at chris-wilson.co.uk> writes:
> > >> 
> > >> > One POSTING_READ of ACTHD may not be enough to ensure that the seqno
> > >> > write has been posted from the GPU and is now visible. So do three!
> > >> >
> > >> 
> > >> Is this about posting read triggering or just adding enough delay
> > >> that the write gets through?
> > >
> > > It's purely about a delay that we guess will cover 99.9999% of cases.
> > 
> > Acked-by: Mika Kuoppala <mika.kuoppala at intel.com>
> 
> Thanks, for checking over the idea. I'm going to apply it to
> topic/core-for-CI for some extended soak testing and see if that
> silences fi-snb-2600

Second run and the miss came back. Boo.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre