[PATCH 04/91] drm/i915: Set guilty-flag on fence after detecting a hang

[Tvrtko Ursulin]

On 05/01/2017 10:34, Chris Wilson wrote:
> The struct dma_fence carries a status field exposed to userspace by
> sync_file. This is inspected after the fence is signaled and can convey
> whether or not the request completed successfully, or in our case if we
> detected a hang during the request (signaled via -EIO in
> SYNC_IOC_FILE_INFO).
>
> v2: Mark all cancelled requests as failed.
>
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> Cc: Mika Kuoppala <mika.kuoppala at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/i915_gem.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index 37107448a42b..1fcce2db86f2 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -2724,6 +2724,8 @@ static void reset_request(struct drm_i915_gem_request *request)
>  		head = 0;
>  	}
>  	memset(vaddr + head, 0, request->postfix - head);
> +
> +	dma_fence_set_error(&request->fence, -EIO);
>  }
>
>  void i915_gem_reset_prepare(struct drm_i915_private *dev_priv)
> @@ -2754,10 +2756,12 @@ static void i915_gem_reset_engine(struct intel_engine_cs *engine)
>  		ring_hung = false;
>  	}
>
> -	if (ring_hung)
> +	if (ring_hung) {
>  		i915_gem_context_mark_guilty(request->ctx);
> -	else
> +		dma_fence_set_error(&request->fence, -EIO);
> +	} else {
>  		i915_gem_context_mark_innocent(request->ctx);
> +	}
>
>  	if (!ring_hung)
>  		return;
>

I was thinking briefly if we could consolidate dma_fence_set_error only 
in reset_request, and call the latter in all cases instead of sometimes, 
but then decided to leave that for later.

Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

Regards,

Tvrtko