[Intel-gfx] [PATCH 04/18] drm/i915: After reset on sanitization, reset the engine backends

[Mika Kuoppala]

Chris Wilson <chris at chris-wilson.co.uk> writes:

> As we reset the GPU on suspend/resume, we also do need to reset the
> engine state tracking so call into the engine backends. This is
> especially important so that we can also sanitize the state tracking
> across resume.
>
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> ---
>  drivers/gpu/drm/i915/i915_gem.c | 24 ++++++++++++++++++++++++
>  1 file changed, 24 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index 7b5544efa0ba..5a7e0b388ad0 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -4955,7 +4955,22 @@ static void assert_kernel_context_is_current(struct drm_i915_private *i915)
>  
>  void i915_gem_sanitize(struct drm_i915_private *i915)
>  {
> +	struct intel_engine_cs *engine;
> +	enum intel_engine_id id;
> +
> +	GEM_TRACE("\n");
> +
>  	mutex_lock(&i915->drm.struct_mutex);
> +
> +	intel_runtime_pm_get(i915);
> +	intel_uncore_forcewake_get(i915, FORCEWAKE_ALL);
> +
> +	/*
> +	 * As we have just resumed the machine and woken the device up from
> +	 * deep PCI sleep (presumably D3_cold), assume the HW has been reset
> +	 * back to defaults, recovering from whatever wedged state we left it
> +	 * in and so worth trying to use the device once more.
> +	 */
>  	if (i915_terminally_wedged(&i915->gpu_error))
>  		i915_gem_unset_wedged(i915);
>  
> @@ -4970,6 +4985,15 @@ void i915_gem_sanitize(struct drm_i915_private *i915)
>  	if (INTEL_GEN(i915) >= 5 && intel_has_gpu_reset(i915))
>  		WARN_ON(intel_gpu_reset(i915, ALL_ENGINES));
>  
> +	/* Reset the submission backend after resume as well as the GPU reset */
> +	for_each_engine(engine, i915, id) {
> +		if (engine->reset.reset)
> +			engine->reset.reset(engine, NULL);
> +	}

The NULL guarantees that it wont try to do any funny things
with the incomplete state.

But what guarantees the the timeline cleanup so that
we don't endup unwinding incomplete requests crap?
-Mika

> +
> +	intel_uncore_forcewake_put(i915, FORCEWAKE_ALL);
> +	intel_runtime_pm_put(i915);
> +
>  	i915_gem_contexts_lost(i915);
>  	mutex_unlock(&i915->drm.struct_mutex);
>  }
> -- 
> 2.17.0
>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx