This is a note to let you know that I've just added the patch titled
drm/i915/dp: Limit SST link rate to <=8.1Gbps
to the 6.7-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-i915-dp-limit-sst-link-rate-to-8.1gbps.patch
and it can be found in the queue-6.7 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From ad26d56d080780bbfcc1696ca0c0cce3e2124ef6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= <ville.syrjala@xxxxxxxxxxxxxxx>
Date: Thu, 8 Feb 2024 17:45:52 +0200
Subject: drm/i915/dp: Limit SST link rate to <=8.1Gbps
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From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
commit ad26d56d080780bbfcc1696ca0c0cce3e2124ef6 upstream.
Limit the link rate to HBR3 or below (<=8.1Gbps) in SST mode.
UHBR (10Gbps+) link rates require 128b/132b channel encoding
which we have not yet hooked up into the SST/no-sideband codepaths.
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20240208154552.14545-1-ville.syrjala@xxxxxxxxxxxxxxx
Reviewed-by: Jani Nikula <jani.nikula@xxxxxxxxx>
(cherry picked from commit 6061811d72e14f41f71b6a025510920b187bfcca)
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/display/intel_dp.c | 3 +++
1 file changed, 3 insertions(+)
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -2275,6 +2275,9 @@ intel_dp_compute_config_limits(struct in
limits->min_rate = intel_dp_common_rate(intel_dp, 0);
limits->max_rate = intel_dp_max_link_rate(intel_dp);
+ /* FIXME 128b/132b SST support missing */
+ limits->max_rate = min(limits->max_rate, 810000);
+
limits->min_lane_count = 1;
limits->max_lane_count = intel_dp_max_lane_count(intel_dp);
Patches currently in stable-queue which might be from ville.syrjala@xxxxxxxxxxxxxxx are
queue-6.7/drm-i915-dp-limit-sst-link-rate-to-8.1gbps.patch
