When I fixed the dp rate selection in:
3b73b168cffd9c392584d3f665021fa2190f8612
drm/amdgpu: fix dp link rate selection (v2)
I accidently dropped the special handling for NUTMEG
DP bridge chips. They require a fixed link rate.
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Ken Wang <Qingqing.Wang@amd.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
unsigned max_lane_num = drm_dp_max_lane_count(dpcd);
unsigned lane_num, i, max_pix_clock;
unsigned max_lane_num = drm_dp_max_lane_count(dpcd);
unsigned lane_num, i, max_pix_clock;
- for (lane_num = 1; lane_num <= max_lane_num; lane_num <<= 1) {
- for (i = 0; i < ARRAY_SIZE(link_rates) && link_rates[i] <= max_link_rate; i++) {
- max_pix_clock = (lane_num * link_rates[i] * 8) / bpp;
+ if (amdgpu_connector_encoder_get_dp_bridge_encoder_id(connector) ==
+ ENCODER_OBJECT_ID_NUTMEG) {
+ for (lane_num = 1; lane_num <= max_lane_num; lane_num <<= 1) {
+ max_pix_clock = (lane_num * 270000 * 8) / bpp;
if (max_pix_clock >= pix_clock) {
*dp_lanes = lane_num;
if (max_pix_clock >= pix_clock) {
*dp_lanes = lane_num;
- *dp_rate = link_rates[i];
+ } else {
+ for (lane_num = 1; lane_num <= max_lane_num; lane_num <<= 1) {
+ for (i = 0; i < ARRAY_SIZE(link_rates) && link_rates[i] <= max_link_rate; i++) {
+ max_pix_clock = (lane_num * link_rates[i] * 8) / bpp;
+ if (max_pix_clock >= pix_clock) {
+ *dp_lanes = lane_num;
+ *dp_rate = link_rates[i];
+ return 0;
+ }
+ }
+ }