drm/radeon: Update IH_RB_RPTR register after each processed interrupt

This might decrease the chance of IH ring buffer overflows.

Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/radeon/r600.c b/drivers/gpu/drm/radeon/r600.c
index 81f3236..ea5c9af 100644
--- a/drivers/gpu/drm/radeon/r600.c
+++ b/drivers/gpu/drm/radeon/r600.c
@@ -4048,6 +4048,7 @@
 		/* wptr/rptr are in bytes! */
 		rptr += 16;
 		rptr &= rdev->ih.ptr_mask;
+		WREG32(IH_RB_RPTR, rptr);
 	}
 	if (queue_hotplug)
 		schedule_work(&rdev->hotplug_work);
@@ -4056,7 +4057,6 @@
 	if (queue_thermal && rdev->pm.dpm_enabled)
 		schedule_work(&rdev->pm.dpm.thermal.work);
 	rdev->ih.rptr = rptr;
-	WREG32(IH_RB_RPTR, rdev->ih.rptr);
 	atomic_set(&rdev->ih.lock, 0);
 
 	/* make sure wptr hasn't changed while processing */