[Intel-gfx] [PATCH 24/46] drm/i915: Do a synchronous switch-to-kernel-context on idling

[Daniele Ceraolo Spurio]

<snip>

> @@ -4481,19 +4471,7 @@ int i915_gem_suspend(struct drm_i915_private *i915)
>   	 * state. Fortunately, the kernel_context is disposable and we do
>   	 * not rely on its state.
>   	 */
> -	if (!i915_terminally_wedged(&i915->gpu_error)) {
> -		ret = i915_gem_switch_to_kernel_context(i915);
> -		if (ret)
> -			goto err_unlock;
> -
> -		ret = i915_gem_wait_for_idle(i915,
> -					     I915_WAIT_INTERRUPTIBLE |
> -					     I915_WAIT_LOCKED |
> -					     I915_WAIT_FOR_IDLE_BOOST,
> -					     HZ / 5);
> -		if (ret == -EINTR)
> -			goto err_unlock;
> -
> +	if (!switch_to_kernel_context_sync(i915)) { >   		/* Forcibly cancel outstanding work and leave the gpu quiet. */
>   		i915_gem_set_wedged(i915);
>   	}

GuC-related question: what's your expectation here in regards to GuC 
status? The current i915 flow expect either uc_reset_prepare() or 
uc_suspend() to be called to clean up the guc status, but we're calling 
neither of them here if the switch is successful. Do you expect the 
resume code to always blank out the GuC status before a reload?

Thanks,
Daniele