From: Meenakshikumar Somasundaram <[email protected]>
[Why] Some mst branches NAK's segment pointer writes with mot disabled. So reset of segment pointer to 0 should be performed with mot enabled. [How] Write segment pointer of mst branch devices with mot enabled. Reviewed-by: Cruise Hung <[email protected]> Signed-off-by: Meenakshikumar Somasundaram <[email protected]> Signed-off-by: Tom Chung <[email protected]> --- drivers/gpu/drm/amd/display/dc/link/link_factory.c | 3 --- .../drm/amd/display/dc/link/protocols/link_dp_capability.c | 6 ++++++ 2 files changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/amd/display/dc/link/link_factory.c b/drivers/gpu/drm/amd/display/dc/link/link_factory.c index 31a73867cd4c..f06af98d46ee 100644 --- a/drivers/gpu/drm/amd/display/dc/link/link_factory.c +++ b/drivers/gpu/drm/amd/display/dc/link/link_factory.c @@ -817,9 +817,6 @@ static bool construct_dpia(struct dc_link *link, link->psr_settings.psr_version = DC_PSR_VERSION_UNSUPPORTED; - /* Some docks seem to NAK I2C writes to segment pointer with mot=0. */ - link->wa_flags.dp_mot_reset_segment = true; - return true; ddc_create_fail: diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_capability.c b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_capability.c index 701afd2d4ab1..750147c52c8a 100644 --- a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_capability.c +++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_capability.c @@ -1867,6 +1867,12 @@ static bool retrieve_link_cap(struct dc_link *link) link->dpcd_caps.is_mst_capable = read_is_mst_supported(link); DC_LOG_DC("%s: MST_Support: %s\n", __func__, str_yes_no(link->dpcd_caps.is_mst_capable)); + /* Some MST docks seem to NAK I2C writes to segment pointer with mot=0. */ + if (link->dpcd_caps.is_mst_capable) + link->wa_flags.dp_mot_reset_segment = true; + else + link->wa_flags.dp_mot_reset_segment = false; + get_active_converter_info(ds_port.byte, link); dp_wa_power_up_0010FA(link, dpcd_data, sizeof(dpcd_data)); -- 2.43.0
