[Intel-gfx] [PATCH] drm/i915/guc: Fix runtime suspend

[Daniele Ceraolo Spurio]

On 5/2/19 1:30 PM, Chris Wilson wrote:
> We are not allowed to rpm_get() inside the runtime-suspend callback, so
> split the intel_uc_suspend() into the core that assumes the caller holds
> the wakeref (intel_uc_runtime_suspend), and one acquires the wakeref as
> necessary (intel_uc_suspend).
> 
> Reported-by: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
> Fixes: 79ffac8599c4 ("drm/i915: Invert the GEM wakeref hierarchy")
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>

Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>

And we now have a new failure to look at that we weren't seeing before 
because the execution was cut short... :(

Daniele

> ---
>   drivers/gpu/drm/i915/i915_drv.c |  2 +-
>   drivers/gpu/drm/i915/intel_uc.c | 25 +++++++++++++++++--------
>   drivers/gpu/drm/i915/intel_uc.h |  1 +
>   3 files changed, 19 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> index 21dac5a09fbe..74e46d129e6c 100644
> --- a/drivers/gpu/drm/i915/i915_drv.c
> +++ b/drivers/gpu/drm/i915/i915_drv.c
> @@ -2886,7 +2886,7 @@ static int intel_runtime_suspend(struct device *kdev)
>   	 */
>   	i915_gem_runtime_suspend(dev_priv);
>   
> -	intel_uc_suspend(dev_priv);
> +	intel_uc_runtime_suspend(dev_priv);
>   
>   	intel_runtime_pm_disable_interrupts(dev_priv);
>   
> diff --git a/drivers/gpu/drm/i915/intel_uc.c b/drivers/gpu/drm/i915/intel_uc.c
> index 01ea36e3150c..1ee70df51627 100644
> --- a/drivers/gpu/drm/i915/intel_uc.c
> +++ b/drivers/gpu/drm/i915/intel_uc.c
> @@ -481,22 +481,31 @@ void intel_uc_reset_prepare(struct drm_i915_private *i915)
>   	intel_uc_sanitize(i915);
>   }
>   
> -void intel_uc_suspend(struct drm_i915_private *i915)
> +void intel_uc_runtime_suspend(struct drm_i915_private *i915)
>   {
>   	struct intel_guc *guc = &i915->guc;
> -	intel_wakeref_t wakeref;
>   	int err;
>   
>   	if (guc->fw.load_status != INTEL_UC_FIRMWARE_SUCCESS)
>   		return;
>   
> -	with_intel_runtime_pm(i915, wakeref) {
> -		err = intel_guc_suspend(guc);
> -		if (err)
> -			DRM_DEBUG_DRIVER("Failed to suspend GuC, err=%d", err);
> +	err = intel_guc_suspend(guc);
> +	if (err)
> +		DRM_DEBUG_DRIVER("Failed to suspend GuC, err=%d", err);
>   
> -		guc_disable_communication(guc);
> -	}
> +	guc_disable_communication(guc);
> +}
> +
> +void intel_uc_suspend(struct drm_i915_private *i915)
> +{
> +	struct intel_guc *guc = &i915->guc;
> +	intel_wakeref_t wakeref;
> +
> +	if (guc->fw.load_status != INTEL_UC_FIRMWARE_SUCCESS)
> +		return;
> +
> +	with_intel_runtime_pm(i915, wakeref)
> +		intel_uc_runtime_suspend(i915);
>   }
>   
>   int intel_uc_resume(struct drm_i915_private *i915)
> diff --git a/drivers/gpu/drm/i915/intel_uc.h b/drivers/gpu/drm/i915/intel_uc.h
> index c92436b1f1c5..3ea06c87dfcd 100644
> --- a/drivers/gpu/drm/i915/intel_uc.h
> +++ b/drivers/gpu/drm/i915/intel_uc.h
> @@ -40,6 +40,7 @@ int intel_uc_init(struct drm_i915_private *dev_priv);
>   void intel_uc_fini(struct drm_i915_private *dev_priv);
>   void intel_uc_reset_prepare(struct drm_i915_private *i915);
>   void intel_uc_suspend(struct drm_i915_private *i915);
> +void intel_uc_runtime_suspend(struct drm_i915_private *i915);
>   int intel_uc_resume(struct drm_i915_private *dev_priv);
>   
>   static inline bool intel_uc_is_using_guc(struct drm_i915_private *i915)
>