drm/amdgpu: disable MMHUB PG for Picasso

commit f626dd0ff0 upstream.

MMHUB PG needs to be disabled for Picasso for stability reasons.

Signed-off-by: Evan Quan <evan.quan@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/gpu/drm/amd/amdgpu/soc15.c

@@ -1273,8 +1273,11 @@ static int soc15_common_early_init(void *handle)
 				AMD_CG_SUPPORT_SDMA_LS |
 				AMD_CG_SUPPORT_VCN_MGCG;
 
+			/*
+			 * MMHUB PG needs to be disabled for Picasso for
+			 * stability reasons.
+			 */
 			adev->pg_flags = AMD_PG_SUPPORT_SDMA |
-				AMD_PG_SUPPORT_MMHUB |
 				AMD_PG_SUPPORT_VCN;
 		} else {
 			adev->cg_flags = AMD_CG_SUPPORT_GFX_MGCG |