The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
Thanks, Sasha
------------------ original commit in Linus's tree ------------------
From 1b5078f01b953a43d6198180ca5b110017315672 Mon Sep 17 00:00:00 2001 From: Zhikai Zhai zhikai.zhai@amd.com Date: Mon, 29 Jan 2024 17:02:18 +0800 Subject: [PATCH] drm/amd/display: Add align done check
[WHY] We Double-check link status if training successful, but miss the lane align status.
[HOW] Add the lane align status check
Cc: Mario Limonciello mario.limonciello@amd.com Cc: Alex Deucher alexander.deucher@amd.com Cc: stable@vger.kernel.org Reviewed-by: Wenjing Liu wenjing.liu@amd.com Acked-by: Aurabindo Pillai aurabindo.pillai@amd.com Signed-off-by: Zhikai Zhai zhikai.zhai@amd.com Tested-by: Daniel Wheeler daniel.wheeler@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com --- .../gpu/drm/amd/display/dc/link/protocols/link_dp_training.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.c b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.c index e06d3c2d89102..e538c67d3ed91 100644 --- a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.c +++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.c @@ -517,6 +517,7 @@ enum link_training_result dp_check_link_loss_status( { enum link_training_result status = LINK_TRAINING_SUCCESS; union lane_status lane_status; + union lane_align_status_updated dpcd_lane_status_updated; uint8_t dpcd_buf[6] = {0}; uint32_t lane;
@@ -532,10 +533,12 @@ enum link_training_result dp_check_link_loss_status( * check lanes status */ lane_status.raw = dp_get_nibble_at_index(&dpcd_buf[2], lane); + dpcd_lane_status_updated.raw = dpcd_buf[4];
if (!lane_status.bits.CHANNEL_EQ_DONE_0 || !lane_status.bits.CR_DONE_0 || - !lane_status.bits.SYMBOL_LOCKED_0) { + !lane_status.bits.SYMBOL_LOCKED_0 || + !dp_is_interlane_aligned(dpcd_lane_status_updated)) { /* if one of the channel equalization, clock * recovery or symbol lock is dropped * consider it as (link has been