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FAILED: patch "[PATCH] drm/amd/display: force toggle rate wa for first link training" failed to apply to 6.6-stable tree

PATCH [email protected] 1 participant 1 message Jan 27, 2024

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Stable branch DRM drivers Radeon and amdgpu DRM drivers AMD display core
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The patch below does not apply to the 6.6-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 <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 5a9a2cc8ae1889c4002850b00fd4fd9691dfac4e
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2024012753-radiation-single-4e58@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..

Possible dependencies:

5a9a2cc8ae18 ("drm/amd/display: force toggle rate wa for first link training for a retimer")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 5a9a2cc8ae1889c4002850b00fd4fd9691dfac4e Mon Sep 17 00:00:00 2001
From: Zhongwei <[email protected]>
Date: Wed, 8 Nov 2023 16:34:36 +0800
Subject: [PATCH] drm/amd/display: force toggle rate wa for first link training
for a retimer

[WHY]
Handover from DMUB to driver does not perform link rate toggle. It might cause link training failure for boot up.

[HOW]
Force toggle rate wa for first link train. link->vendor_specific_lttpr_link_rate_wa should be zero then.

Cc [email protected] # 6.1+
Reviewed-by Michael Strauss <[email protected]>
Acked-by Hamza Mahfooz <[email protected]>
Signed-off-by Zhongwei <[email protected]>
Signed-off-by Alex Deucher <[email protected]>
drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training_fixed_vs_pe_retimer.c +3 -3
index fd8f6f198146..68096d12f52f 100644
@@ -115,7 +115,7 @@ static enum link_training_result perform_fixed_vs_pe_nontransparent_training_seq
 		lt_settings->cr_pattern_time = 16000;
 
 	/* Fixed VS/PE specific: Toggle link rate */
-	apply_toggle_rate_wa = (link->vendor_specific_lttpr_link_rate_wa == target_rate);
+	apply_toggle_rate_wa = ((link->vendor_specific_lttpr_link_rate_wa == target_rate) || (link->vendor_specific_lttpr_link_rate_wa == 0));
 	target_rate = get_dpcd_link_rate(&lt_settings->link_settings);
 	toggle_rate = (target_rate == 0x6) ? 0xA : 0x6;
 

@@ -271,7 +271,7 @@ enum link_training_result dp_perform_fixed_vs_pe_training_sequence_legacy(
 	/* Vendor specific: Toggle link rate */
 	toggle_rate = (rate == 0x6) ? 0xA : 0x6;
 
-	if (link->vendor_specific_lttpr_link_rate_wa == rate) {
+	if (link->vendor_specific_lttpr_link_rate_wa == rate || link->vendor_specific_lttpr_link_rate_wa == 0) {
 		core_link_write_dpcd(
 				link,
 				DP_LINK_BW_SET,

@@ -617,7 +617,7 @@ enum link_training_result dp_perform_fixed_vs_pe_training_sequence(
 	/* Vendor specific: Toggle link rate */
 	toggle_rate = (rate == 0x6) ? 0xA : 0x6;
 
-	if (link->vendor_specific_lttpr_link_rate_wa == rate) {
+	if (link->vendor_specific_lttpr_link_rate_wa == rate || link->vendor_specific_lttpr_link_rate_wa == 0) {
 		core_link_write_dpcd(
 				link,
 				DP_LINK_BW_SET,