drm/amd/display: Fix preferred link rate for NUTMEG
authorTimur Kristóf <timur.kristof@gmail.com>
Fri, 29 May 2026 09:09:08 +0000 (11:09 +0200)
committerAlex Deucher <alexander.deucher@amd.com>
Wed, 15 Jul 2026 13:15:37 +0000 (09:15 -0400)
When there is a preferred link rate setting, it needs to be
applied to both the current and initial link rate.
This was regressed by a "coding style" fix, which caused
the current link rate to not respect the preferred value.

This commit restores the functionality of NUTMEG,
the DP bridge encoder found on old APUs such as Kaveri.

Fixes: a62346043a89 ("drm/amd/display: Fix coding style issue")
Closes: https://gitlab.freedesktop.org/drm/amd/-/work_items/5465
Cc: Chuanyu Tseng <Chuanyu.Tseng@amd.com>
Reviewed-by: Fangzhi Zuo <Jerry.Zuo@amd.com>
Signed-off-by: Timur Kristóf <timur.kristof@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_capability.c

index d232971..5d3b526 100644 (file)
@@ -756,8 +756,10 @@ static bool decide_dp_link_settings(struct dc_link *link, struct dc_link_setting
        if (req_bw > dp_link_bandwidth_kbps(link, &link->verified_link_cap))
                return false;
 
-       if (link->preferred_link_setting.link_rate != LINK_RATE_UNKNOWN)
+       if (link->preferred_link_setting.link_rate != LINK_RATE_UNKNOWN) {
                initial_link_setting.link_rate = link->preferred_link_setting.link_rate;
+               current_link_setting.link_rate = link->preferred_link_setting.link_rate;
+       }
 
        /* search for the minimum link setting that:
         * 1. is supported according to the link training result