[Intel-gfx] [PATCH v2 1/2] drm/i915/guc: fix GuC suspend/resume

[Michal Wajdeczko]

On Wed, 17 Oct 2018 00:46:47 +0200, Daniele Ceraolo Spurio  
<daniele.ceraolospurio at intel.com> wrote:

> The ENTER/EXIT_S_STATE actions queue the save/restore operation in GuC
> FW and then return, so waiting on the H2G is not enough to guarantee
> GuC is done.
> When all the processing is done, GuC writes 0 to scratch register 14,
> so we can poll on that. Note that GuC does not ensure that the value
> in the register is different from 0 while the action is in progress
> so we need to take care of that ourselves as well.
>
> v2: improve comment, return early on GuC error and improve error
>     message (Michal)
>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Michal Wajdeczko <michal.wajdeczko at intel.com>
> Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
> Acked-by: Chris Wilson <chris at chris-wilson.co.uk>
> ---

Reviewed-by: Michal Wajdeczko <michal.wajdeczko at intel.com>

Michal