[Intel-gfx] [PATCH] drm/i915: Suppress the "Failed to idle" warning for gem_eio

[Tvrtko Ursulin]

On 08/03/2019 13:45, Chris Wilson wrote:
> It is debatable whether having an error message on suspend for forcibly
> cancelling outstanding work is worthwhile. We want to know if it occurs
> in the wild (as we will then have to reconsider the approach!), but
> equally is not fatal across suspend, as upon resume we automatically
> clear the wedged status.
> 
> However, CI does trigger this scenario with gem_eio/suspend; as there we
> are intentionally wedging the device upon suspend. The dilemma is how
> not to trigger a failure report for the dmesg spam, for which the
> quickest response is to suppress the warning in the kernel. I'd rather
> mark it as accepted in gem_eio, but for now detecting when gem_eio is
> playing games and cancelling the warning for that case seems a barely
> acceptable hack.
> 
> Testcase: igt/gem_eio/suspend
> Reference: 5861b013e2c7 ("drm/i915: Do a synchronous switch-to-kernel-context on idling")
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> ---
>   drivers/gpu/drm/i915/i915_gem.c | 9 ++++++---
>   1 file changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index e7e8c236bc8e..8e0833b01ddc 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -2848,10 +2848,13 @@ static bool switch_to_kernel_context_sync(struct drm_i915_private *i915,
>   		result = false;
>   
>   	if (!result) {
> +		if (i915_modparams.reset) { /* hide the warning for gem_eio */
> +			dev_err(i915->drm.dev,
> +				"Failed to idle engines, declaring wedged!\n");
> +			GEM_TRACE_DUMP();
> +		}
> +
>   		/* Forcibly cancel outstanding work and leave the gpu quiet. */
> -		dev_err(i915->drm.dev,
> -			"Failed to idle engines, declaring wedged!\n");
> -		GEM_TRACE_DUMP();
>   		i915_gem_set_wedged(i915);
>   	}
>   
> 

I think dev_notice when reset is disabled would make sense from being 
informative point of view, but this is also OK.

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

Regards,

Tvrtko