[Intel-gfx] [PATCH 2/5] drm/i915/guc: Release all client doorbells on suspend and acquire on resume

[Chris Wilson]

Quoting Sagar Arun Kamble (2017-11-05 13:39:40)
> Before GT device suspend, i915 should release GuC client doorbells by
> stopping doorbell controller snooping and doorbell deallocation through
> GuC. They need to be acquired again on resume. This will also resolve
> the driver unload issue with GuC, where doorbell deallocation was being
> done post GEM suspend.
> Release function is called from guc_suspend prior to sending sleep action
> during runtime and drm suspend. Acquiral is different in runtime and drm
> resume paths as on drm resume we are currently doing full reinit. Release
> should be done in synchronization with acquire hence GuC suspend/resume
> along with doorbell release/acquire should be under struct_mutex. Upcoming
> suspend and resume restructuring for GuC will update these changes.
> 
> Signed-off-by: Sagar Arun Kamble <sagar.a.kamble at intel.com>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Michał Winiarski <michal.winiarski at intel.com>
> Cc: Michel Thierry <michel.thierry at intel.com>
> Cc: Michal Wajdeczko <michal.wajdeczko at intel.com>
> Cc: Arkadiusz Hiler <arkadiusz.hiler at intel.com>
> Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/i915_drv.c            |  3 +++
>  drivers/gpu/drm/i915/i915_gem.c            |  5 +++--
>  drivers/gpu/drm/i915/i915_guc_submission.c | 20 ++++++++++++++++----
>  drivers/gpu/drm/i915/i915_guc_submission.h |  2 ++
>  drivers/gpu/drm/i915/intel_guc.c           |  2 ++
>  5 files changed, 26 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> index e7e9e06..3df8a7d 100644
> --- a/drivers/gpu/drm/i915/i915_drv.c
> +++ b/drivers/gpu/drm/i915/i915_drv.c
> @@ -47,6 +47,7 @@
>  #include <drm/i915_drm.h>
>  
>  #include "i915_drv.h"
> +#include "i915_guc_submission.h"
>  #include "i915_trace.h"
>  #include "i915_vgpu.h"
>  #include "intel_drv.h"
> @@ -2615,6 +2616,8 @@ static int intel_runtime_resume(struct device *kdev)
>  
>         intel_guc_resume(dev_priv);
>  
> +       i915_guc_clients_acquire_doorbells(&dev_priv->guc);

intel_guc_acquire_doorbells();

Though, if we need to specialise between resume and runtime_resume, I
suggest adding intel_guc_resume() and intel_guc_runtime_resume() entry
points. (We probably should find a better way to distinguish those two
paths, system_resume vs runtime_resume?)
-Chris