[Intel-gfx] [PATCH v2 3/3] drm/i915: Clean up GPU hang message

[Dave Gordon]

On 11/12/15 22:59, Chris Wilson wrote:
> Remove some redundant kernel messages as we deduce a hung GPU and
> capture the error state.
>
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> ---
>   drivers/gpu/drm/i915/i915_irq.c | 16 ++++++----------
>   1 file changed, 6 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
> index 4cfbd694b3a8..365d4872a67d 100644
> --- a/drivers/gpu/drm/i915/i915_irq.c
> +++ b/drivers/gpu/drm/i915/i915_irq.c
> @@ -2963,7 +2963,7 @@ static void i915_hangcheck_elapsed(struct work_struct *work)
>   	struct drm_device *dev = dev_priv->dev;
>   	struct intel_engine_cs *ring;
>   	int i;
> -	int busy_count = 0, rings_hung = 0;
> +	int busy_count = 0;
>   	bool stuck[I915_NUM_RINGS] = { 0 };
>   #define BUSY 1
>   #define KICK 5
> @@ -3057,17 +3057,13 @@ static void i915_hangcheck_elapsed(struct work_struct *work)
>   	}
>
>   	for_each_ring(ring, dev_priv, i) {
> -		if (ring->hangcheck.score >= HANGCHECK_SCORE_RING_HUNG) {
> -			DRM_INFO("%s on %s\n",
> -				 stuck[i] ? "stuck" : "no progress",
> -				 ring->name);
> -			rings_hung++;
> -		}
> +		if (ring->hangcheck.score >= HANGCHECK_SCORE_RING_HUNG)
> +			return i915_handle_error(dev, true,
> +						 "%s on %s",
> +						 stuck[i] ? "No progress" : "Hang",
> +						 ring->name);
>   	}
>
> -	if (rings_hung)
> -		return i915_handle_error(dev, true, "Ring hung");
> -
>   	/* Reset timer in case GPU hangs without another request being added */
>   	if (busy_count)
>   		i915_queue_hangcheck(dev_priv);

This version provides less information (in dmesg & syslog) in the case 
that multiple rings have (been detected as) hung. Does this ever happen? 
Is the original more useful for finding bugs in hangcheck itself? If 
this is a test that has disabled error state capture (because it's 
*trying* to hang one or more rings) can we still know how many rings 
have been diagnosed as hung?

.Dave.