drm/radeon: fix halting UVD

Removing the clock/power or resetting the VCPU can cause
hangs if that happens in the middle of a register write.

Stall the memory and register bus before putting the VCPU
into reset. Keep it in reset when unloading the module or
suspending.

Signed-off-by: Christian König <christian.koenig@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/radeon/si.c b/drivers/gpu/drm/radeon/si.c
index 6ca9046..242c1ac 100644
--- a/drivers/gpu/drm/radeon/si.c
+++ b/drivers/gpu/drm/radeon/si.c
@@ -6621,7 +6621,7 @@
 	si_cp_enable(rdev, false);
 	cayman_dma_stop(rdev);
 	if (rdev->has_uvd) {
-		r600_uvd_rbc_stop(rdev);
+		r600_uvd_stop(rdev);
 		radeon_uvd_suspend(rdev);
 	}
 	si_irq_suspend(rdev);
@@ -6763,8 +6763,10 @@
 	radeon_vm_manager_fini(rdev);
 	radeon_ib_pool_fini(rdev);
 	radeon_irq_kms_fini(rdev);
-	if (rdev->has_uvd)
+	if (rdev->has_uvd) {
+		r600_uvd_stop(rdev);
 		radeon_uvd_fini(rdev);
+	}
 	si_pcie_gart_fini(rdev);
 	r600_vram_scratch_fini(rdev);
 	radeon_gem_fini(rdev);