drm/amd/display: Avoid trying AUX transactions on disconnected ports

[ Upstream commit deb24e64c8881c462b29e2c69afd9e6669058be5 ]

[Why & How]
Observe that we try to access DPCD 0x600h of disconnected DP ports.
In order not to wasting time on retrying these ports, call
dpcd_write_rx_power_ctrl() after checking its connection status.

Reviewed-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Wayne Lin <Wayne.Lin@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/gpu/drm/amd/display/dc/link/link_dpms.c b/drivers/gpu/drm/amd/display/dc/link/link_dpms.c
index 273a3be6d593af910e4b89a259c049d960540f8e..f16cba4b9119dff4d076b474c5ed5da9113264a1 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/link/link_dpms.c
+++ b/drivers/gpu/drm/amd/display/dc/link/link_dpms.c
@@ -140,7 +140,8 @@ void link_blank_dp_stream(struct dc_link *link, bool hw_init)
                                }
                }
 
-               if ((!link->wa_flags.dp_keep_receiver_powered) || hw_init)
+               if (((!link->wa_flags.dp_keep_receiver_powered) || hw_init) &&
+                       (link->type != dc_connection_none))
                        dpcd_write_rx_power_ctrl(link, false);
        }
 }