[Intel-gfx] [PATCH v4] drm/i915/execlists: Always clear preempt status on cancelling all

[Chris Wilson]

Quoting Chris Wilson (2018-07-16 13:56:46)
> On reset/wedging, we cancel all pending replies from the HW and we also
> want to cancel an outstanding preemption event. Since we use the same
> function to cancel the pending replies for reset and for a preemption
> event, we can simply clear the active tracking for all.
> 
> v2: Keep execlists_user_end() markup for wedging
> v3: Move assignment to inline to hide the bare assignment.
> v4: Alternate version, use user_end for clearing all leftovers
> 
> Fixes: 60a943245413 ("drm/i915/execlists: Drop clear_gtiir() on GPU reset")
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> ---
>  drivers/gpu/drm/i915/intel_lrc.c        | 2 +-
>  drivers/gpu/drm/i915/intel_ringbuffer.h | 6 ++++++
>  2 files changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
> index 6fef9d130d55..f9fb32efb97f 100644
> --- a/drivers/gpu/drm/i915/intel_lrc.c
> +++ b/drivers/gpu/drm/i915/intel_lrc.c
> @@ -388,7 +388,7 @@ execlists_user_begin(struct intel_engine_execlists *execlists,
>  inline void
>  execlists_user_end(struct intel_engine_execlists *execlists)
>  {
> -       execlists_clear_active(execlists, EXECLISTS_ACTIVE_USER);
> +       execlists_clear_all_active(execlists);

While the doing a simple assignment is nice, we lose that direct link
with user == ACTIVE_USER.

On the whole, I think it's acceptable to use assignment here rather than
clearing the single bit.
-Chris