[Intel-gfx] [PATCH v2 1/5] drm/i915/uc: Don't enable communication twice on resume

[Chris Wilson]

Quoting Daniele Ceraolo Spurio (2019-07-31 00:07:39)
> When coming out of S3/S4 we sanitize and re-init the HW, which includes
> enabling communication during uc_init_hw. We therefore don't want to do
> that again in uc_resume and can just tell GuC to reload its state.
> 
> v2: split uc_resume and uc_runtime_resume to match the suspend
>     functions and to better differentiate the expected state in the 2
>     scenarios (Chris)
> 
> Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
> Cc: Michal Wajdeczko <michal.wajdeczko at intel.com>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> ---
>  drivers/gpu/drm/i915/gt/uc/intel_uc.c | 35 +++++++++++++++++++++++++--
>  drivers/gpu/drm/i915/gt/uc/intel_uc.h |  1 +
>  drivers/gpu/drm/i915/i915_drv.c       |  4 +--
>  3 files changed, 36 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_uc.c b/drivers/gpu/drm/i915/gt/uc/intel_uc.c
> index 6eb8bb3fa252..657fdcb70d00 100644
> --- a/drivers/gpu/drm/i915/gt/uc/intel_uc.c
> +++ b/drivers/gpu/drm/i915/gt/uc/intel_uc.c
> @@ -233,11 +233,20 @@ static void guc_disable_interrupts(struct intel_guc *guc)
>         guc->interrupts.disable(guc);
>  }
>  
> +#ifdef CONFIG_DRM_I915_DEBUG_GEM
> +static bool guc_communication_enabled(struct intel_guc *guc)
> +{
> +       return guc->send != intel_guc_send_nop;
> +}
> +#endif
> +
>  static int guc_enable_communication(struct intel_guc *guc)
>  {
>         struct drm_i915_private *i915 = guc_to_gt(guc)->i915;
>         int ret;
>  
> +       GEM_BUG_ON(guc_communication_enabled(guc));
> +
>         ret = intel_guc_ct_enable(&guc->ct);
>         if (ret)
>                 return ret;
> @@ -550,7 +559,7 @@ void intel_uc_suspend(struct intel_uc *uc)
>                 intel_uc_runtime_suspend(uc);
>  }
>  
> -int intel_uc_resume(struct intel_uc *uc)
> +static int __uc_resume(struct intel_uc *uc, bool enable_communication)
>  {
>         struct intel_guc *guc = &uc->guc;
>         int err;
> @@ -558,7 +567,11 @@ int intel_uc_resume(struct intel_uc *uc)
>         if (!intel_guc_is_running(guc))
>                 return 0;
>  
> -       guc_enable_communication(guc);
> +       /* Make sure we enable communication if and only if it's disabled */
> +       GEM_BUG_ON(enable_communication == guc_communication_enabled(guc));
> +
> +       if (enable_communication)
> +               guc_enable_communication(guc);
>  
>         err = intel_guc_resume(guc);
>         if (err) {
> @@ -568,3 +581,21 @@ int intel_uc_resume(struct intel_uc *uc)
>  
>         return 0;
>  }
> +
> +int intel_uc_resume(struct intel_uc *uc)
> +{
> +       /*
> +        * When coming out of S3/S4 we sanitize and re-init the HW, so
> +        * communication is already re-enabled at this point.
> +        */
> +       return __uc_resume(uc, false);
> +}
> +
> +int intel_uc_runtime_resume(struct intel_uc *uc)
> +{
> +       /*
> +        * During runtime resume we don't sanitize, so we need to re-init
> +        * communication as well.
> +        */
> +       return __uc_resume(uc, true);
> +}
> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_uc.h b/drivers/gpu/drm/i915/gt/uc/intel_uc.h
> index fe3362fd7706..25da51e95417 100644
> --- a/drivers/gpu/drm/i915/gt/uc/intel_uc.h
> +++ b/drivers/gpu/drm/i915/gt/uc/intel_uc.h
> @@ -47,6 +47,7 @@ void intel_uc_reset_prepare(struct intel_uc *uc);
>  void intel_uc_suspend(struct intel_uc *uc);
>  void intel_uc_runtime_suspend(struct intel_uc *uc);
>  int intel_uc_resume(struct intel_uc *uc);
> +int intel_uc_runtime_resume(struct intel_uc *uc);
>  
>  static inline bool intel_uc_is_using_guc(struct intel_uc *uc)
>  {
> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> index f2d3d754af37..761726818a22 100644
> --- a/drivers/gpu/drm/i915/i915_drv.c
> +++ b/drivers/gpu/drm/i915/i915_drv.c
> @@ -2950,7 +2950,7 @@ static int intel_runtime_suspend(struct device *kdev)
>  
>                 intel_runtime_pm_enable_interrupts(dev_priv);
>  
> -               intel_uc_resume(&dev_priv->gt.uc);
> +               intel_uc_runtime_resume(&dev_priv->gt.uc);
>  
>                 intel_gt_init_swizzling(&dev_priv->gt);
>                 i915_gem_restore_fences(dev_priv);
> @@ -3047,7 +3047,7 @@ static int intel_runtime_resume(struct device *kdev)
>  
>         intel_runtime_pm_enable_interrupts(dev_priv);
>  
> -       intel_uc_resume(&dev_priv->gt.uc);
> +       intel_uc_runtime_resume(&dev_priv->gt.uc);

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