On Tue, Aug 17, 2021 at 11:21:27AM +0200, Daniel Vetter wrote:
> On Mon, Aug 16, 2021 at 06:51:23AM -0700, Matthew Brost wrote:
> > Progagating errors to dependent fences is wrong, don't do it. Selftest
> > in following patch exposes this bug.
>
> Please explain what "this bug" is, it's hard to read minds, especially at
> a distance in spacetime :-)
>
Not a very good explaination.
> > Fixes: 8e9f84cf5cac ("drm/i915/gt: Propagate change in error status to children on unhold")
>
> I think it would be better to outright revert this, instead of just
> disabling it like this.
>
I tried revert and git did some really odd things that I couldn't
resolve, hence the new patch.
> Also please cite the dma_fence error propagation revert from Jason:
>
> commit 93a2711cddd5760e2f0f901817d71c93183c3b87
> Author: Jason Ekstrand <jason@xxxxxxxxxxxxxx>
> Date: Wed Jul 14 14:34:16 2021 -0500
>
> Revert "drm/i915: Propagate errors on awaiting already signaled fences"
>
> Maybe in full, if you need the justification.
>
Will site.
> > Signed-off-by: Matthew Brost <matthew.brost@xxxxxxxxx>
> > Cc: <stable@xxxxxxxxxxxxxxx>
>
> Unless "this bug" is some real world impact thing I wouldn't put cc:
> stable on this.
Got it.
Matt
> -Daniel
> > ---
> > drivers/gpu/drm/i915/gt/intel_execlists_submission.c | 4 ----
> > 1 file changed, 4 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
> > index de5f9c86b9a4..cafb0608ffb4 100644
> > --- a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
> > +++ b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
> > @@ -2140,10 +2140,6 @@ static void __execlists_unhold(struct i915_request *rq)
> > if (p->flags & I915_DEPENDENCY_WEAK)
> > continue;
> >
> > - /* Propagate any change in error status */
> > - if (rq->fence.error)
> > - i915_request_set_error_once(w, rq->fence.error);
> > -
> > if (w->engine != rq->engine)
> > continue;
> >
> > --
> > 2.32.0
> >
>
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch
