[Intel-gfx] [PATCH] drm/i915/guc: Do not bypass forcewakes in i915_guc_submit

[Chris Wilson]

On Thu, Nov 17, 2016 at 09:17:35AM +0000, Tvrtko Ursulin wrote:
> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> 
> Commit ed4596ea992d ("drm/i915/guc: WA to address the Ringbuffer
> coherency issue"), based on incorrect assumptions from a partialy
> broken commit 0dd356bb6ff5 ("drm/i915: Eliminate Gen9 special
> case") used POSTING_READ_FW instead of the POSTING_READ. With the
> latter buggy commit fixed this call site needs fixing as well.

The theory here is that we don't need the powerwell to force the write
from CPU to be visible before another agent.

I missed the report, so I am genuinely interested in knowing whether the
theory about the write being posted without the powerwll.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre