From 16930318f55f8a9b1a766d54a6a087a21c00a6dd Mon Sep 17 00:00:00 2001 From: Wesley Chalmers Date: Thu, 16 May 2019 12:40:25 -0400 Subject: [PATCH 2066/2940] drm/amd/display: Update link rate from DPCD 10 [WHY] Some panels return a link rate of 0 (unknown) in DPCD 0. In this case, an appropriate mode cannot be set, and certain panels will show corruption as they are forced to use a mode they do not support. [HOW] Read DPCD 10 in the case where supported link rate from DPCD 0 is unknown, and pass that value on to the reported link rate. This re-introduces behaviour present in previous versions that appears to have been accidentally removed. Signed-off-by: Wesley Chalmers Reviewed-by: Anthony Koo Acked-by: Bhawanpreet Lakha --- drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c index 65d6caedbd82..2d519e5fc3ea 100644 --- a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c +++ b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c @@ -1624,8 +1624,7 @@ static bool decide_edp_link_settings(struct dc_link *link, struct dc_link_settin uint32_t link_bw; if (link->dpcd_caps.dpcd_rev.raw < DPCD_REV_14 || - link->dpcd_caps.edp_supported_link_rates_count == 0 || - link->dc->config.optimize_edp_link_rate == false) { + link->dpcd_caps.edp_supported_link_rates_count == 0) { *link_setting = link->verified_link_cap; return true; } @@ -2609,7 +2608,8 @@ void detect_edp_sink_caps(struct dc_link *link) memset(supported_link_rates, 0, sizeof(supported_link_rates)); if (link->dpcd_caps.dpcd_rev.raw >= DPCD_REV_14 && - link->dc->config.optimize_edp_link_rate) { + (link->dc->config.optimize_edp_link_rate || + link->reported_link_cap.link_rate == LINK_RATE_UNKNOWN)) { // Read DPCD 00010h - 0001Fh 16 bytes at one shot core_link_read_dpcd(link, DP_SUPPORTED_LINK_RATES, supported_link_rates, sizeof(supported_link_rates)); @@ -2624,6 +2624,9 @@ void detect_edp_sink_caps(struct dc_link *link) link_rate = linkRateInKHzToLinkRateMultiplier(link_rate_in_khz); link->dpcd_caps.edp_supported_link_rates[link->dpcd_caps.edp_supported_link_rates_count] = link_rate; link->dpcd_caps.edp_supported_link_rates_count++; + + if (link->reported_link_cap.link_rate < link_rate) + link->reported_link_cap.link_rate = link_rate; } } } -- 2.17.1