Bug 110683

The CI Bug Log issue associated to this bug has been updated.

### New filters associated

* ICL: igt@i915_selftest@live_hangcheck - dmesg-fail - failed to complete request after reset
  - https://intel-gfx-ci.01.org/tree/drm-tip/IGT_4983/fi-icl-y/igt@i915_selftest@live_hangcheck.html

The HW bogosity is:

<7> [533.332880] [drm:execlists_resume [i915]] STOP_RING still set in RING_MI_MODE

One occurrence, attributed to HW issues. Lowering priority and let's keep watching.

(In reply to Francesco Balestrieri from comment #3)
> One occurrence, attributed to HW issues. Lowering priority and let's keep
> watching.

It has occurred a few times. Not always the same test, but if reset fails, this error tends to show up.

One small breakthrough: https://patchwork.freedesktop.org/patch/318310/?series=63752&rev=1

commit c30d5dc653cbc78f9b634b7b72e25057a68c527c (HEAD -> drm-intel-next-queued, drm-intel/for-linux-next, drm-intel/drm-intel-next-queued)
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Tue Jul 16 13:49:28 2019 +0100

    drm/i915/gt: Push engine stopping into reset-prepare
    
    Push the engine stop into the back reset_prepare (where it already was!)
    This allows us to avoid dangerously setting the RING registers to 0 for
    logical contexts. If we clear the register on a live context, those
    invalid register values are recorded in the logical context state and
    replayed (with hilarious results).
    
    Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
    Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
    Link: https://patchwork.freedesktop.org/patch/msgid/20190716124931.5870-2-chris@chris-wilson.co.uk

commit fff8102aaed59014cb2d8034bdca231185496b16
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Tue Jul 16 13:49:29 2019 +0100

    drm/i915/execlists: Process interrupted context on reset
    
    By stopping the rings, we may trigger an arbitration point resulting in
    a premature context-switch (i.e. a completion event before the request
    is actually complete). This clears the active context before the reset,
    but we must remember to rewind the incomplete context for replay upon
    resume.
    
    Fixes: 1863e3020ab5 ("drm/i915/execlists: Always reset the context's RING registers")
    Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
    Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
    Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
    Link: https://patchwork.freedesktop.org/patch/msgid/20190716124931.5870-3-chris@chris-wilson.co.uk

Hopefully. The mystery of STOP_RING persisting over reset remains, but I expect that to be mere noise; an incidental HW detail (unless it means that the reset itself didn't happen...)

Not seen on drm-tip. So closing and archiving this.

The CI Bug Log issue associated to this bug has been archived.

New failures matching the above filters will not be associated to this bug anymore.