diff mbox series

drm/amd/display: Add dp_decide_lane_settings() to ensure compatibility

Message ID 20250320032725.909-1-vulab@iscas.ac.cn (mailing list archive)
State New
Headers show
Series drm/amd/display: Add dp_decide_lane_settings() to ensure compatibility | expand

Commit Message

Wentao Liang March 20, 2025, 3:27 a.m. UTC
The dp_perform_128b_132b_channel_eq_done_sequence() calls
dp_get_lane_status_and_lane_adjust() but lacks dp_decide_lane_settings().
The dp_get_lane_status_and_lane_adjust() and dp_decide_lane_settings()
functions are essential for DisplayPort link training in the Linux kernel,
with the former retrieving lane status and adjustment needs, and the
latter determining optimal lane configurations. This omission risks
compatibility issues, particularly with lower-quality cables or displays,
as the system cannot dynamically adjust to hardware limitations,
potentially leading to failed connections. Add dp_decide_lane_settings()
to enable adaptive lane configuration.

Fixes: 630168a97314 ("drm/amd/display: move dp link training logic to link_dp_training")
Cc: stable@vger.kernel.org # 6.3+
Signed-off-by: Wentao Liang <vulab@iscas.ac.cn>
---
 .../amd/display/dc/link/protocols/link_dp_training_128b_132b.c  | 2 ++
 1 file changed, 2 insertions(+)
diff mbox series

Patch

diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training_128b_132b.c b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training_128b_132b.c
index db87cfe37b5c..99aae3e43106 100644
--- a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training_128b_132b.c
+++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training_128b_132b.c
@@ -176,6 +176,8 @@  static enum link_training_result dp_perform_128b_132b_cds_done_sequence(
 		wait_time += lt_settings->cds_pattern_time;
 		status = dp_get_lane_status_and_lane_adjust(link, lt_settings, dpcd_lane_status,
 						&dpcd_lane_status_updated, dpcd_lane_adjust, DPRX);
+		dp_decide_lane_settings(lt_settings, dpcd_lane_adjust,
+				lt_settings->hw_lane_settings, lt_settings->dpcd_lane_settings);
 		if (status != DC_OK) {
 			result = LINK_TRAINING_ABORT;
 		} else if (dp_is_symbol_locked(lt_settings->link_settings.lane_count, dpcd_lane_status) &&