[Intel-gfx] [CI 1/2] drm/i915/uc: Extract common code from GuC stop/disable comm

[Chris Wilson]

Quoting Fernando Pacheco (2019-08-29 18:41:53)
> During normal driver unload we attempt to disable GuC communication
> while it is currently stopped. This results in a nop'd call to
> intel_guc_ct_disable within guc_disable_communication because
> stop/disable rely on the same flag to prevent further comms with CT.
> 
> We can avoid the call to disable and still leave communication in a
> satisfactory state by extracting a set of shared steps from stop/disable.
> This set can include guc_disable_interrupts as we do not require the
> single caller of guc_stop_communication to be atomic:
> "drm/i915/selftests: Fixup atomic reset checking".
> 
> This situation (stop -> disable) only occurs during intel_uc_fini_hw,
> so during fini, call guc_disable_communication only if currently enabled.
> The symmetric calls to enable/disable remain unmodified for all other
> scenarios.
> 
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=110943
> Signed-off-by: Fernando Pacheco <fernando.pacheco at intel.com>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Michal Wajdeczko <michal.wajdeczko at intel.com>
> Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
> Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>

Thanks for the bugfix and review, pushed.
-Chris