Re: [PATCH 3/4] drm/i915/guc: Flag an error if an engine reset fails

[Daniele Ceraolo Spurio <daniele.ceraolospurio@xxxxxxxxx>]

On 12/10/2021 10:58 PM, John.C.Harrison@xxxxxxxxx wrote:
> From: John Harrison <John.C.Harrison@xxxxxxxxx>
>
> If GuC encounters an error during engine reset, the i915 driver
> promotes to full GT reset. This includes an info message about why the
> reset is happening. However, that is not treated as a failure by any
> of the CI systems because resets are an expected occurrance during
> testing. This kind of failure is a major problem and should never
> happen. So, complain more loudly and make sure CI notices.
>
> Signed-off-by: John Harrison <John.C.Harrison@xxxxxxxxx>
> ---
>   drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c | 14 +++++++++++---
>   1 file changed, 11 insertions(+), 3 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 97311119da6f..6015815f1da0 100644
> --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
> +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
> @@ -4018,11 +4018,12 @@ int intel_guc_engine_failure_process_msg(struct intel_guc *guc,
>   					 const u32 *msg, u32 len)
>   {
>   	struct intel_engine_cs *engine;
> +	struct intel_gt *gt = guc_to_gt(guc);
>   	u8 guc_class, instance;
>   	u32 reason;
>   
>   	if (unlikely(len != 3)) {
> -		drm_err(&guc_to_gt(guc)->i915->drm, "Invalid length %u", len);
> +		drm_err(&gt->i915->drm, "Invalid length %u", len);
>   		return -EPROTO;
>   	}
>   
> @@ -4032,12 +4033,19 @@ int intel_guc_engine_failure_process_msg(struct intel_guc *guc,
>   
>   	engine = guc_lookup_engine(guc, guc_class, instance);
>   	if (unlikely(!engine)) {
> -		drm_err(&guc_to_gt(guc)->i915->drm,
> +		drm_err(&gt->i915->drm,
>   			"Invalid engine %d:%d", guc_class, instance);
>   		return -EPROTO;
>   	}
>   
> -	intel_gt_handle_error(guc_to_gt(guc), engine->mask,
> +	/*
> +	 * This is an unexpected failure of a hardware feature. So, log a real
> +	 * error message not just the informational that comes with the reset.
> +	 */
> +	drm_err(&gt->i915->drm, "GuC engine reset request failed on %d:%d (%s) because %d",

In the error handling called below, the reason is logged as 0x%08x, so 
IMO we should do the same here for consistency.
With that:

Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@xxxxxxxxx>

Daniele

> +		guc_class, instance, engine->name, reason);
> +
> +	intel_gt_handle_error(gt, engine->mask,
>   			      I915_ERROR_CAPTURE,
>   			      "GuC failed to reset %s (reason=0x%08x)\n",
>   			      engine->name, reason);