This is a note to let you know that I've just added the patch titled
drm/amd/display: Clear dpcd_sink_ext_caps if not set
to the 6.6-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-amd-display-clear-dpcd_sink_ext_caps-if-not-set.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 923bbfe6c888812db1088d684bd30c24036226d2 Mon Sep 17 00:00:00 2001
From: Paul Hsieh <paul.hsieh@xxxxxxx>
Date: Wed, 25 Oct 2023 10:53:35 +0800
Subject: drm/amd/display: Clear dpcd_sink_ext_caps if not set
From: Paul Hsieh <paul.hsieh@xxxxxxx>
commit 923bbfe6c888812db1088d684bd30c24036226d2 upstream.
[WHY]
Some eDP panels' ext caps don't set initial values
and the value of dpcd_addr (0x317) is random.
It means that sometimes the eDP can be OLED, miniLED and etc,
and cause incorrect backlight control interface.
[HOW]
Add remove_sink_ext_caps to remove sink ext caps (HDR, OLED and etc)
Cc: Mario Limonciello <mario.limonciello@xxxxxxx>
Cc: Alex Deucher <alexander.deucher@xxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Reviewed-by: Anthony Koo <anthony.koo@xxxxxxx>
Acked-by: Alex Hung <alex.hung@xxxxxxx>
Signed-off-by: Paul Hsieh <paul.hsieh@xxxxxxx>
Tested-by: Daniel Wheeler <daniel.wheeler@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/amd/display/dc/dc_types.h | 1 +
drivers/gpu/drm/amd/display/dc/link/link_detection.c | 3 +++
2 files changed, 4 insertions(+)
--- a/drivers/gpu/drm/amd/display/dc/dc_types.h
+++ b/drivers/gpu/drm/amd/display/dc/dc_types.h
@@ -189,6 +189,7 @@ struct dc_panel_patch {
unsigned int disable_fams;
unsigned int skip_avmute;
unsigned int mst_start_top_delay;
+ unsigned int remove_sink_ext_caps;
};
struct dc_edid_caps {
--- a/drivers/gpu/drm/amd/display/dc/link/link_detection.c
+++ b/drivers/gpu/drm/amd/display/dc/link/link_detection.c
@@ -1085,6 +1085,9 @@ static bool detect_link_and_local_sink(s
if (sink->edid_caps.panel_patch.skip_scdc_overwrite)
link->ctx->dc->debug.hdmi20_disable = true;
+ if (sink->edid_caps.panel_patch.remove_sink_ext_caps)
+ link->dpcd_sink_ext_caps.raw = 0;
+
if (dc_is_hdmi_signal(link->connector_signal))
read_scdc_caps(link->ddc, link->local_sink);
Patches currently in stable-queue which might be from paul.hsieh@xxxxxxx are
queue-6.6/drm-amd-display-clear-dpcd_sink_ext_caps-if-not-set.patch
