This is a note to let you know that I've just added the patch titled
drm/amd/display: Restore guard against default backlight value < 1 nit
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-restore-guard-against-default-backlight-value-1-nit.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 b96ab339ee50470d13a1faa6ad94d2218a7cd49f Mon Sep 17 00:00:00 2001
From: Mario Limonciello <mario.limonciello@xxxxxxx>
Date: Wed, 6 Dec 2023 12:08:26 -0600
Subject: drm/amd/display: Restore guard against default backlight value < 1 nit
From: Mario Limonciello <mario.limonciello@xxxxxxx>
commit b96ab339ee50470d13a1faa6ad94d2218a7cd49f upstream.
Mark reports that brightness is not restored after Xorg dpms screen blank.
This behavior was introduced by commit d9e865826c20 ("drm/amd/display:
Simplify brightness initialization") which dropped the cached backlight
value in display code, but also removed code for when the default value
read back was less than 1 nit.
Restore this code so that the backlight brightness is restored to the
correct default value in this circumstance.
Reported-by: Mark Herbert <mark.herbert42@xxxxxxxxx>
Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/3031
Cc: stable@xxxxxxxxxxxxxxx
Cc: Camille Cho <camille.cho@xxxxxxx>
Cc: Krunoslav Kovac <krunoslav.kovac@xxxxxxx>
Cc: Hamza Mahfooz <hamza.mahfooz@xxxxxxx>
Fixes: d9e865826c20 ("drm/amd/display: Simplify brightness initialization")
Acked-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/amd/display/dc/link/protocols/link_edp_panel_control.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/gpu/drm/amd/display/dc/link/protocols/link_edp_panel_control.c
+++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_edp_panel_control.c
@@ -280,8 +280,8 @@ bool set_default_brightness_aux(struct d
if (link && link->dpcd_sink_ext_caps.bits.oled == 1) {
if (!read_default_bl_aux(link, &default_backlight))
default_backlight = 150000;
- // if > 5000, it might be wrong readback
- if (default_backlight > 5000000)
+ // if < 1 nits or > 5000, it might be wrong readback
+ if (default_backlight < 1000 || default_backlight > 5000000)
default_backlight = 150000;
return edp_set_backlight_level_nits(link, true,
Patches currently in stable-queue which might be from mario.limonciello@xxxxxxx are
queue-6.6/drm-amd-display-disable-psr-su-on-parade-0803-tcon-again.patch
queue-6.6/drm-amd-display-restore-guard-against-default-backlight-value-1-nit.patch
queue-6.6/drm-amdgpu-sdma5.2-add-begin-end_use-ring-callbacks.patch
queue-6.6/hid-i2c-hid-add-idea5002-to-i2c_hid_acpi_blacklist.patch
