This is a note to let you know that I've just added the patch titled drm/amd/display: Properly handle additional cases where DCN is not supported to the 6.1-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drm-amd-display-properly-handle-additional-cases-whe.patch and it can be found in the queue-6.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 28cfca1f62e5b32d72394f71cfc66f432a760f0a Author: Alex Deucher <alexander.deucher@xxxxxxx> Date: Wed Jan 25 14:35:16 2023 -0500 drm/amd/display: Properly handle additional cases where DCN is not supported [ Upstream commit 6fc547a5a2ef5ce05b16924106663ab92f8f87a7 ] There could be boards with DCN listed in IP discovery, but no display hardware actually wired up. In this case the vbios display table will not be populated. Detect this case and skip loading DM when we detect it. v2: Mark DCN as harvested as well so other display checks elsewhere in the driver are handled properly. Cc: Aurabindo Pillai <aurabindo.pillai@xxxxxxx> Reviewed-by: Aurabindo Pillai <aurabindo.pillai@xxxxxxx> Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c index 988b1c947aefc..2d63248d09bbb 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -4526,6 +4526,17 @@ DEVICE_ATTR_WO(s3_debug); static int dm_early_init(void *handle) { struct amdgpu_device *adev = (struct amdgpu_device *)handle; + struct amdgpu_mode_info *mode_info = &adev->mode_info; + struct atom_context *ctx = mode_info->atom_context; + int index = GetIndexIntoMasterTable(DATA, Object_Header); + u16 data_offset; + + /* if there is no object header, skip DM */ + if (!amdgpu_atom_parse_data_header(ctx, index, NULL, NULL, NULL, &data_offset)) { + adev->harvest_ip_mask |= AMD_HARVEST_IP_DMU_MASK; + dev_info(adev->dev, "No object header, skipping DM\n"); + return -ENOENT; + } switch (adev->asic_type) { #if defined(CONFIG_DRM_AMD_DC_SI)