On 12/01/2023 02:53, John.C.Harrison@xxxxxxxxx wrote:
From: John Harrison <John.C.Harrison@xxxxxxxxx>
Engine resets are supposed to never fail. But in the case when one
does (due to unknown reasons that normally come down to a missing
w/a), it is useful to get as much information out of the system as
possible. Given that the GuC effectively dies on such a situation, it
is not possible to get a guilty context notification back. So do a
manual search instead. Given that GuC is dead, this is safe because
GuC won't be changing the engine state asynchronously.
Signed-off-by: John Harrison <John.C.Harrison@xxxxxxxxx>
---
.../gpu/drm/i915/gt/uc/intel_guc_submission.c | 17 +++++++++++++++--
1 file changed, 15 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
index b436dd7f12e42..99d09e3394597 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
@@ -4754,11 +4754,24 @@ static void reset_fail_worker_func(struct work_struct *w)
guc->submission_state.reset_fail_mask = 0;
spin_unlock_irqrestore(&guc->submission_state.lock, flags);
- if (likely(reset_fail_mask))
+ if (likely(reset_fail_mask)) {
+ struct intel_engine_cs *engine;
+ enum intel_engine_id id;
+
+ /*
+ * GuC is toast at this point - it dead loops after sending the failed
+ * reset notification. So need to manually determine the guilty context.
+ * Note that it should be safe/reliable to do this here because the GuC
+ * is toast and will not be scheduling behind the KMD's back.
+ */
+ for_each_engine_masked(engine, gt, reset_fail_mask, id)
+ intel_guc_find_hung_context(engine);
+
intel_gt_handle_error(gt, reset_fail_mask,
I915_ERROR_CAPTURE,
- "GuC failed to reset engine mask=0x%x\n",
+ "GuC failed to reset engine mask=0x%x",
reset_fail_mask);
+ }
}
int intel_guc_engine_failure_process_msg(struct intel_guc *guc,
This one I don't feel "at home" enough to r-b. Just a question - can we
be sure at this point that GuC is 100% stuck and there isn't a chance it
somehow comes alive and starts running in parallel (being driven in
parallel by a different "thread" in i915), interfering with the
assumption made in the comment?
Regards,
Tvrtko
