From 4de0bfe67bc98fb2a1115bc58ef3b9bc21717629 Mon Sep 17 00:00:00 2001 From: Jimmy Kizito Date: Wed, 25 Aug 2021 19:12:08 -0400 Subject: [PATCH] drm/amd/display: Fix link training fallback logic [Why] Link training should fail if stream bandwidth exceeds link bandwidth. [How] Correct fallback logic and use named variables to make intention clear. Reviewed-by: Meenakshikumar Somasundaram Reviewed-by: Jun Lei Acked-by: Rodrigo Siqueira Signed-off-by: Jimmy Kizito Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 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 7ea5051093404..e3f102425fee6 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 @@ -2462,12 +2462,16 @@ bool perform_link_training_with_retries( if (type == dc_connection_none) break; } else if (do_fallback) { + uint32_t req_bw; + uint32_t link_bw; + decide_fallback_link_setting(*link_setting, ¤t_setting, status); /* Fail link training if reduced link bandwidth no longer meets * stream requirements. */ - if (dc_bandwidth_in_kbps_from_timing(&stream->timing) < - dc_link_bandwidth_kbps(link, ¤t_setting)) + req_bw = dc_bandwidth_in_kbps_from_timing(&stream->timing); + link_bw = dc_link_bandwidth_kbps(link, ¤t_setting); + if (req_bw > link_bw) break; } -- 2.30.2