Chris Wilson <ch...@chris-wilson.co.uk> writes: > If we fail to reset the GPU, we declare the machine wedged. However, the > GPU may well still be running in the background with an in-flight > request. So despite our efforts in cleaning up the request queue and > faking the breadcrumb in the HWSP, the GPU may eventually write the > in-flght seqno there breaking all of our assumptions and throwing the > driver into a deep turmoil, wedging beyond wedged. > > To avoid this we ideally want to reset the GPU. Since that has already > failed, make sure the rings have the stop bit set instead. This is part > of the normal GPU reset sequence, but that is actually disabled by > igt/gem_eio to force the wedged state. If we assume the worst, we must > poke at the bit again before we give up. > > v2: Move the intel_gpu_reset() from set-wedged in the reset error path > into i915_gem_set_wedged() itself. Even if the reset fails (e.g. if it is > disabled by gem_eio), it still tries to make sure the engines are > stopped. For i915_gem_set_wedged() callers from outside of i915_reset(), > this should make sure the GPU is disabled while the driver is marked as > being wedged. > > Testcase: igt/gem_eio > Signed-off-by: Chris Wilson <ch...@chris-wilson.co.uk> > Cc: Mika Kuoppala <mika.kuopp...@linux.intel.com> > Cc: Michał Winiarski <michal.winiar...@intel.com> > Cc: Michal Wajdeczko <michal.wajdec...@intel.com> > Cc: Michel Thierry <michel.thie...@intel.com> > --- > drivers/gpu/drm/i915/i915_drv.c | 1 - > drivers/gpu/drm/i915/i915_gem.c | 3 +++ > 2 files changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c > index f03555efc520..3df5193487f3 100644 > --- a/drivers/gpu/drm/i915/i915_drv.c > +++ b/drivers/gpu/drm/i915/i915_drv.c > @@ -1995,7 +1995,6 @@ void i915_reset(struct drm_i915_private *i915, unsigned > int flags) > error: > i915_gem_set_wedged(i915); > i915_retire_requests(i915); > - intel_gpu_reset(i915, ALL_ENGINES); > goto finish; > } > > diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c > index 2fbd622bba30..802df8e1a544 100644 > --- a/drivers/gpu/drm/i915/i915_gem.c > +++ b/drivers/gpu/drm/i915/i915_gem.c > @@ -3246,6 +3246,9 @@ void i915_gem_set_wedged(struct drm_i915_private *i915) > } > i915->caps.scheduler = 0; > > + /* Even if the GPU reset fails, it should still stop the engines */ > + intel_gpu_reset(i915, ALL_ENGINES); > +
Comment is very welcome in here as modparm.reset usage isn't so transparent. Reviewed-by: Mika Kuoppala <mika.kuopp...@linux.intel.com> > /* > * Make sure no one is running the old callback before we proceed with > * cancelling requests and resetting the completion tracking. Otherwise > -- > 2.16.2 _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx
