From: Agustin Gutierrez <agustin.gutierrez@xxxxxxx> [Why] Some older MST hubs do not report DPCD registers according to specification. [How] This change re-applies change: c5365554514 "drm/amd/display: dsc mst re-compute pbn for changes on hub". With an additional check for these older MST devices. Reviewed-by: Swapnil Patel <swapnil.patel@xxxxxxx> Acked-by: Tom Chung <chiahsuan.chung@xxxxxxx> Signed-off-by: Agustin Gutierrez <agustin.gutierrez@xxxxxxx> --- .../amd/display/amdgpu_dm/amdgpu_dm_mst_types.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git 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 index 5542e7d63b81..affedce9de6b 100644 --- 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 @@ -1209,6 +1209,12 @@ static bool is_dsc_need_re_compute( if (dc_link->type != dc_connection_mst_branch) return false; + /* add a check for older MST DSC with no virtual DPCDs */ + if (needs_dsc_aux_workaround(dc_link) && + (!(dc_link->dpcd_caps.dsc_caps.dsc_basic_caps.fields.dsc_support.DSC_SUPPORT || + dc_link->dpcd_caps.dsc_caps.dsc_basic_caps.fields.dsc_support.DSC_PASSTHROUGH_SUPPORT))) + return false; + for (i = 0; i < MAX_PIPES; i++) stream_on_link[i] = NULL; @@ -1230,12 +1236,8 @@ static bool is_dsc_need_re_compute( continue; /* - * Check if cached virtual MST DSC caps are available and DSC is supported - * this change takes care of newer MST DSC capable devices that report their - * DPCD caps as per specifications in their Virtual DPCD registers. - - * TODO: implement the check for older MST DSC devices that do not conform to - * specifications. + * check if cached virtual MST DSC caps are available and DSC is supported + * as per specifications in their Virtual DPCD registers. */ if (!(aconnector->dc_sink->dsc_caps.dsc_dec_caps.is_dsc_supported || aconnector->dc_link->dpcd_caps.dsc_caps.dsc_basic_caps.fields.dsc_support.DSC_PASSTHROUGH_SUPPORT)) -- 2.34.1
