[Intel-gfx] [PATCH 3/3] drm/i915/bdw: Use the GEN8 SRM when qeueing a flip

[Chris Wilson]

On Mon, Apr 07, 2014 at 11:20:14PM +0100, Damien Lespiau wrote:
> On Mon, Apr 07, 2014 at 01:59:17PM -0700, Ben Widawsky wrote:
> > Cool. This explains the bad DERRMR values I was seeing in in error
> > states. I'm honestly didn't check if we actually need an SRM for BDW
> > still, but I'll assume you did check.
> 
> Just checked, the LRI command still mentions that we need the SRM after
> writes to the display engine.

It shouldn't explain the DERRMR values being incorrect though aiui. The
SRM is to prevent system hangs from two concurrent writes, which never
satisfied me as to how that prevents two different MMIO paths from
accessing the same register cacheline simultaneously. Magic.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre