Hi Krzysztof,
>
> Hi Nitin,
>
> [...]
>
> > - if (!stop_ring(engine)) {
> > + /*
> > + * Sometimes engine head failed to set to zero even after
> > writing
> into it.
> > + * Use wait_for_atomic() with 20ms delay to let engine resumes
> from
> > + * correct RING_HEAD. Experimented different values and
> determined
> > + * that 20ms works best based on testing.
> > + */
> > + if (wait_for_atomic((!stop_ring(engine) == 0), 20)) {
> > drm_err(&engine->i915->drm,
> > "failed to set %s head to zero "
> > "ctl %08x head %08x tail %08x start %08x\n",
>
> I am wondering if xcs_resume() calling stop_ring() too would benefit from
> having
> this timeout on hand as well. That would require moving
> wait_for_atomic((!stop_ring(engine) == 0), 20) along with your comment to a
> separate wrapper function.
> What do you think?
In xcs_resume(), there is no need for a timeout for stop_ring(), as we have not
encountered any issues/errors in xcs_resume().
So, I think, currently there is no need for a separate wrapper function.
- Nitin
>
> Best Regards
> Krzysztof
