From: Lyude Paul <lyude@xxxxxxxxxx> commit 1119e1f9636b76aef14068c7fd0b4d55132b86b8 upstream. Looks like I made a pretty big mistake here without noticing: it seems when I moved the assignments of mst_state->pbn_div I completely missed the fact that the reason for us calling drm_dp_mst_update_slots() earlier was to account for the fact that we need to call this function using info from the root MST connector, instead of just trying to do this from each MST encoder's atomic check function. Otherwise, we end up filling out all of DC's link information with zeroes. So, let's restore that and hopefully fix this DSC regression. Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/2171 Signed-off-by: Lyude Paul <lyude@xxxxxxxxxx> Signed-off-by: Harry Wentland <harry.wentland@xxxxxxx> Fixes: 4d07b0bc4034 ("drm/display/dp_mst: Move all payload info into the atomic state") Cc: stable@xxxxxxxxxxxxxxx # 6.1 Reviewed-by: Harry Wentland <harry.wentland@xxxxxxx> Tested-by: Didier Raboud <odyx@xxxxxxxxxx> Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 24 ++++++++++++ drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c | 5 -- 2 files changed, 24 insertions(+), 5 deletions(-) --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -9393,6 +9393,8 @@ static int amdgpu_dm_atomic_check(struct struct drm_connector_state *old_con_state, *new_con_state; struct drm_crtc *crtc; struct drm_crtc_state *old_crtc_state, *new_crtc_state; + struct drm_dp_mst_topology_mgr *mgr; + struct drm_dp_mst_topology_state *mst_state; struct drm_plane *plane; struct drm_plane_state *old_plane_state, *new_plane_state; enum dc_status status; @@ -9648,6 +9650,28 @@ static int amdgpu_dm_atomic_check(struct lock_and_validation_needed = true; } +#if defined(CONFIG_DRM_AMD_DC_DCN) + /* set the slot info for each mst_state based on the link encoding format */ + for_each_new_mst_mgr_in_state(state, mgr, mst_state, i) { + struct amdgpu_dm_connector *aconnector; + struct drm_connector *connector; + struct drm_connector_list_iter iter; + u8 link_coding_cap; + + drm_connector_list_iter_begin(dev, &iter); + drm_for_each_connector_iter(connector, &iter) { + if (connector->index == mst_state->mgr->conn_base_id) { + aconnector = to_amdgpu_dm_connector(connector); + link_coding_cap = dc_link_dp_mst_decide_link_encoding_format(aconnector->dc_link); + drm_dp_mst_update_slots(mst_state, link_coding_cap); + + break; + } + } + drm_connector_list_iter_end(&iter); + } +#endif + /** * Streams and planes are reset when there are changes that affect * bandwidth. Anything that affects bandwidth needs to go through --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c @@ -896,11 +896,6 @@ static int compute_mst_dsc_configs_for_l if (IS_ERR(mst_state)) return PTR_ERR(mst_state); - mst_state->pbn_div = dm_mst_get_pbn_divider(dc_link); -#if defined(CONFIG_DRM_AMD_DC_DCN) - drm_dp_mst_update_slots(mst_state, dc_link_dp_mst_decide_link_encoding_format(dc_link)); -#endif - /* Set up params */ for (i = 0; i < dc_state->stream_count; i++) { struct dc_dsc_policy dsc_policy = {0};
