[Intel-gfx] [PATCH v4 15/16] drm/i915: Immediately process a reset before starting waiting

[Tvrtko Ursulin]

On 23/02/2017 07:44, Chris Wilson wrote:
> As we handoff the GPU reset to the waiter, we need to check we don't
> miss a wakeup if it has already been sent prior to us starting the wait.
>
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> ---
>  drivers/gpu/drm/i915/i915_gem_request.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_gem_request.c b/drivers/gpu/drm/i915/i915_gem_request.c
> index ee601e13e28a..eaa333a35f7c 100644
> --- a/drivers/gpu/drm/i915/i915_gem_request.c
> +++ b/drivers/gpu/drm/i915/i915_gem_request.c
> @@ -1081,8 +1081,10 @@ long i915_wait_request(struct drm_i915_gem_request *req,
>  	trace_i915_gem_request_wait_begin(req, flags);
>
>  	add_wait_queue(&req->execute, &exec);
> -	if (flags & I915_WAIT_LOCKED)
> +	if (flags & I915_WAIT_LOCKED) {
>  		add_wait_queue(errq, &reset);
> +		__i915_wait_request_check_and_reset(req);
> +	}
>
>  	intel_wait_init(&wait);
>
> @@ -1120,7 +1122,8 @@ long i915_wait_request(struct drm_i915_gem_request *req,
>  		goto complete;
>
>  	set_current_state(state);
> -	if (intel_engine_add_wait(req->engine, &wait))
> +	if (intel_engine_add_wait(req->engine, &wait) ||
> +	    flags & I915_WAIT_LOCKED)
>  		/* In order to check that we haven't missed the interrupt
>  		 * as we enabled it, we need to kick ourselves to do a
>  		 * coherent check on the seqno before we sleep.
>

Didn't figure this second bit - what's happening here?

Regards,

Tvrtko