Merge "msm: kgsl: Fix gdsc disable timeout during reset"

drivers/gpu/msm/adreno_a6xx.c

@@ -1272,7 +1272,15 @@ static const char *a6xx_fault_block_uche(struct kgsl_device *device,
 	unsigned int uche_client_id = 0;
 	static char str[40];
 
-	mutex_lock(&device->mutex);
+	/*
+	 * Smmu driver takes a vote on CX gdsc before calling the kgsl
+	 * pagefault handler. If there is contention for device mutex in this
+	 * path and the dispatcher fault handler is holding this lock, trying
+	 * to turn off CX gdsc will fail during the reset. So to avoid blocking
+	 * here, try to lock device mutex and return if it fails.
+	 */
+	if (!mutex_trylock(&device->mutex))
+		return "UCHE: unknown";
 
 	if (!kgsl_state_is_awake(device)) {
 		mutex_unlock(&device->mutex);