From af68153ffe8c4f778ba9cbe1d1725a939ab94576 Mon Sep 17 00:00:00 2001 From: Ran Shi Date: Wed, 6 Dec 2023 14:52:24 -0500 Subject: drm/amd/display: allow DP40 cables to do UHBR13.5 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 Acked-by: Aurabindo Pillai Signed-off-by: Ran Shi Signed-off-by: Alex Deucher --- .../drm/amd/display/dc/link/protocols/link_dp_capability.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) (limited to 'drivers/gpu/drm/amd/display/dc/link') 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; } -- cgit v1.2.3