[AMD Official Use Only - Internal Distribution Only] Reviewed-by: Joseph Gravenor ________________________________ From: Liu, Zhan Sent: Monday, February 10, 2020 4:08 PM To: amd-gfx@lists.freedesktop.org ; Liu, Zhan ; Gravenor, Joseph Subject: [PATCH] drm/amd/display: Add aconnector condition check for dpcd read [Why] core_link_read_dpcd() will invoke dm_helpers_dp_read_dpcd(), which needs to read dpcd info with the help of aconnector. If aconnector (dc->links[i]->prev) is NULL, then dpcd status cannot be read. As a result, dpcd read fails and a line of error will be printed out in dmesg.log as: "*ERROR* Failed to found connector for link!" [How] Make sure that aconnector (dc->links[i]->prev) is not NULL, then read dpcd status. Signed-off-by: Zhan Liu --- .../amd/display/dc/dcn10/dcn10_hw_sequencer.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c index 42fcfee2c31b..92e1574073fd 100644 --- a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c +++ b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c @@ -1331,11 +1331,20 @@ void dcn10_init_hw(struct dc *dc) if (dc->links[i]->connector_signal != SIGNAL_TYPE_DISPLAY_PORT) { continue; } - /* if any of the displays are lit up turn them off */ - status = core_link_read_dpcd(dc->links[i], DP_SET_POWER, - &dpcd_power_state, sizeof(dpcd_power_state)); - if (status == DC_OK && dpcd_power_state == DP_POWER_STATE_D0) { - dp_receiver_power_ctrl(dc->links[i], false); + + /* + * core_link_read_dpcd() will invoke dm_helpers_dp_read_dpcd(), + * which needs to read dpcd info with the help of aconnector. + * If aconnector (dc->links[i]->prev) is NULL, then dpcd status + * cannot be read. + */ + if (dc->links[i]->priv) { + /* if any of the displays are lit up turn them off */ + status = core_link_read_dpcd(dc->links[i], DP_SET_POWER, + &dpcd_power_state, sizeof(dpcd_power_state)); + if (status == DC_OK && dpcd_power_state == DP_POWER_STATE_D0) { + dp_receiver_power_ctrl(dc->links[i], false); + } } } } -- 2.17.1