From: Ran Shi <ran.shi@xxxxxxx>
why:
With DP2.1a expansion we are allowing DP40 cables to do UHBR13.5
how:
Assume UHBR10 means UHBR13.5 also for unknown cable type and
passive cable type.
Reviewed-by: George Shen <george.shen@xxxxxxx>
Acked-by: Aurabindo Pillai <aurabindo.pillai@xxxxxxx>
Signed-off-by: Ran Shi <ran.shi@xxxxxxx>
---
.../display/dc/link/protocols/link_dp_capability.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)
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 db87aa7b5c90..3c5334cdb3fb 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
@@ -412,12 +412,18 @@ static enum dc_link_rate get_cable_max_link_rate(struct dc_link *link)
{
enum dc_link_rate cable_max_link_rate = LINK_RATE_UNKNOWN;
- if (link->dpcd_caps.cable_id.bits.UHBR10_20_CAPABILITY & DP_UHBR20)
+ if (link->dpcd_caps.cable_id.bits.UHBR10_20_CAPABILITY & DP_UHBR20) {
cable_max_link_rate = LINK_RATE_UHBR20;
- else if (link->dpcd_caps.cable_id.bits.UHBR13_5_CAPABILITY)
+ } else if (link->dpcd_caps.cable_id.bits.UHBR13_5_CAPABILITY) {
cable_max_link_rate = LINK_RATE_UHBR13_5;
- else if (link->dpcd_caps.cable_id.bits.UHBR10_20_CAPABILITY & DP_UHBR10)
- cable_max_link_rate = LINK_RATE_UHBR10;
+ } else if (link->dpcd_caps.cable_id.bits.UHBR10_20_CAPABILITY & DP_UHBR10) {
+ // allow DP40 cables to do UHBR13.5 for passive or unknown cable type
+ if (link->dpcd_caps.cable_id.bits.CABLE_TYPE < 2) {
+ cable_max_link_rate = LINK_RATE_UHBR13_5;
+ } else {
+ cable_max_link_rate = LINK_RATE_UHBR10;
+ }
+ }
return cable_max_link_rate;
}
--
2.39.2
