[Intel-gfx] [PATCH 2/4] drm/i915/guc: Grab RPM wakelock while disabling GuC interrupts

[Chris Wilson]

Quoting Sagar Arun Kamble (2018-01-22 08:26:02)
> Disabling GuC interrupts involves access to GuC IRQ control registers
> hence ensure device is RPM awake.
> 
> v2: Add comment about need to synchronize flush work and log runtime
>     destroy
> 
> v3: Moved patch earlier in the series and removed comment about future
> work. (Tvrtko)
> 
> v4-v5: Rebase.
> 
> Signed-off-by: Sagar Arun Kamble <sagar.a.kamble at intel.com>
> Cc: Michal Wajdeczko <michal.wajdeczko at intel.com>
> Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
> Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/intel_guc_log.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/intel_guc_log.c b/drivers/gpu/drm/i915/intel_guc_log.c
> index 9e5600355..4039912 100644
> --- a/drivers/gpu/drm/i915/intel_guc_log.c
> +++ b/drivers/gpu/drm/i915/intel_guc_log.c
> @@ -694,7 +694,10 @@ void i915_guc_log_unregister(struct drm_i915_private *dev_priv)
>  
>         mutex_lock(&dev_priv->drm.struct_mutex);
>         /* GuC logging is currently the only user of Guc2Host interrupts */
> +       intel_runtime_pm_get(dev_priv);
>         gen9_disable_guc_interrupts(dev_priv);

Do we have/want assert_rpm_wakelock_held() in
gen9_disable_guc_interrupts() ?

Are we really locking the interrupts on/off with struct_mutex?
-Chris