[Intel-gfx] [PATCH 05/20] drm/i915: Cancel reset-engine if we couldn't find an active request

[Chris Wilson]

On Mon, May 15, 2017 at 10:31:58PM +0100, Chris Wilson wrote:
> On Mon, May 15, 2017 at 02:20:01PM -0700, Michel Thierry wrote:
> > @@ -2827,21 +2830,34 @@ int i915_gem_reset_prepare_engine(struct intel_engine_cs *engine)
> >  
> >  	if (engine_stalled(engine)) {
> >  		request = i915_gem_find_active_request(engine);
> > -		if (request && request->fence.error == -EIO)
> > -			err = -EIO; /* Previous reset failed! */
> > +
> > +		if (request) {
> > +			if (request->fence.error == -EIO)
> > +				return ERR_PTR(-EIO); /* Previous reset failed! */
> > +
> > +			if (__i915_gem_request_completed(request,
> > +							 engine->hangcheck.seqno))
> 
> This is not the seqno for the request, so this is incorrect. It will
> judge that the request was preempted (as hangcheck.seqno must be less
> thn request->global_seqno) and so conclude that the request was never
> completed.
> 
> You just want if (i915_gem_request_completed(request))

Also not here. This pardon check should be deferred to the caller just
before commiting to thre reset. In the case of global reset, we want to
gather up all the engines' active requests first, complete our
preparations and then double check the engine was hung.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre