The patch below does not apply to the 5.15-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
--
2.43.0