drm/i915/guc: Flush context destruction worker at suspend

When suspending, flush the context-guc-id
deregistration worker at the final stages of
intel_gt_suspend_late when we finally call gt_sanitize
that eventually leads down to __uc_sanitize so that
the deregistration worker doesn't fire off later as
we reset the GuC microcontroller.

Signed-off-by: Alan Previn <alan.previn.teres.alexis@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Tested-by: Mousumi Jana <mousumi.jana@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231228045558.536585-2-alan.previn.teres.alexis@intel.com

drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c

@@ -1613,6 +1613,11 @@ static void guc_flush_submissions(struct intel_guc *guc)
 	spin_unlock_irqrestore(&sched_engine->lock, flags);
 }
 
+void intel_guc_submission_flush_work(struct intel_guc *guc)
+{
+	flush_work(&guc->submission_state.destroyed_worker);
+}
+
 static void guc_flush_destroyed_contexts(struct intel_guc *guc);
 
 void intel_guc_submission_reset_prepare(struct intel_guc *guc)

drivers/gpu/drm/i915/gt/uc/intel_guc_submission.h

@@ -38,6 +38,8 @@ int intel_guc_wait_for_pending_msg(struct intel_guc *guc,
 				   bool interruptible,
 				   long timeout);
 
+void intel_guc_submission_flush_work(struct intel_guc *guc);
+
 static inline bool intel_guc_submission_is_supported(struct intel_guc *guc)
 {
 	return guc->submission_supported;

drivers/gpu/drm/i915/gt/uc/intel_uc.c

@@ -690,6 +690,8 @@ void intel_uc_suspend(struct intel_uc *uc)
 		return;
 	}
 
+	intel_guc_submission_flush_work(guc);
+
 	with_intel_runtime_pm(&uc_to_gt(uc)->i915->runtime_pm, wakeref) {
 		err = intel_guc_suspend(guc);
 		if (err)