date:20210123

[Kernel-packages] [Bug 1912887] Re: Acer Aspire 5742g backlight brightness level is not saved on shutdown

2021-01-23 Thread unti1x

I made a couple more tests and here is what I've found out.

When the backlight is managed by radeon, writing to
/sys/class/backlight/radeon_bl0/brightness doesn't do anything. Although
changing brightness with Fn+Left/Fn+Right works but the value in
/sys/class/backlight/radeon_bl0/brightness doesn't match the actual
brightness at all: it can be 250 but the screen would be really dim and
vice versa.

When I use the kernel without radeon and drm so the backlight is managed
by acpi_video, writing to "/sys/class/backlight/acpi_video0/brightness"
works fine, the value is saved and restored properly unless it was set
to the maximum.

In both cases the brightness is reset on shutdown to the lowest possible
value and it's always the same on the bios boot screen.

--
You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux in Ubuntu.
https://bugs.launchpad.net/bugs/1912887

Title:
Acer Aspire 5742g backlight brightness level is not saved on shutdown

Status in linux package in Ubuntu:
Confirmed

Bug description:
Initial state: backlight brightness is at normal value. Booting to
ubuntu, it's still fine. Reboot. Brightness level is set to the lowest
possible value. Meanwhile /sys/class/backlight/radeon_bl0/brightness
shows 255 as usual. Using keyboard controls or brightness widget fixes
it until the next reboot.

The problem appears since 13.04, every release before it including
12.10 and 12.04.2 with kernels up to 3.5.*. Moreover these releases
automatically fix the wrong state.

Kernels from 3.8 don't work. I couldn't find any kernels between these
versions, they are just disappeared from the wild. The problem also
appears in other systems released after 2012 including FreeBSD,
OpenBSD, Gentoo, CRUX and HaikuOS. Windows 7 works fine.

It's probably not the problem with radeon driver because I have the
same issue with fglrx or without both.

When booting with acpi_backlight=vendor new backlight device named acer-wmi
appears. Running the following command changes the actual brightness:
echo 8 > /sys/class/backlight/acer-wmi/brightness

Booting with video.use_bios_initial_backlight=0 doesn't do anything,
brightness controls work fine.

Booting with "acpi_osi=" partially fixes the issue: backlight is being
restored to the maximal value but not saved on shutdown. Brightness
controls work fine but MATE's widget doesn't display the level, only
message "No External Display" (acpi_osi=Linux doesn't have this
issue).

Booting with video.use_native_backlight=1 doesn't change anything, the
controls work fine.

Files from https://wiki.kubuntu.org/Kernel/Debugging/Backlight are
attached (I can't attach more than one file so I had to pack them)

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: linux-image-5.4.0-59-generic 5.4.0-59.65
ProcVersionSignature: Ubuntu 5.4.0-59.65-generic 5.4.78
Uname: Linux 5.4.0-59-generic x86_64
ApportVersion: 2.20.11-0ubuntu27.14
Architecture: amd64
AudioDevicesInUse:
USERPID ACCESS COMMAND
/dev/snd/controlC0: unti1x 1121 F pulseaudio
/dev/snd/controlC1: unti1x 1121 F pulseaudio
CasperMD5CheckResult: skip
CurrentDesktop: MATE
Date: Sat Jan 23 12:26:04 2021
InstallationDate: Installed on 2021-01-04 (18 days ago)
InstallationMedia: Ubuntu-MATE 20.04.1 LTS "Focal Fossa" - Release amd64
(20200731)
MachineType: Acer Aspire 5742G
ProcFB: 0 radeondrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.4.0-59-generic
root=UUID=b0baea2a-cc5b-4ee6-88e7-cce32fd6d019 ro acpi_osi=Linux quiet splash
vt.handoff=7
RelatedPackageVersions:
linux-restricted-modules-5.4.0-59-generic N/A
linux-backports-modules-5.4.0-59-generic N/A
linux-firmware1.187.7
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 08/13/2012
dmi.bios.vendor: Acer
dmi.bios.version: V1.30
dmi.board.asset.tag: Base Board Asset Tag
dmi.board.name: Aspire 5742G
dmi.board.vendor: Acer
dmi.board.version: V1.30
dmi.chassis.type: 10
dmi.chassis.vendor: Acer
dmi.chassis.version: V1.30
dmi.modalias:
dmi:bvnAcer:bvrV1.30:bd08/13/2012:svnAcer:pnAspire5742G:pvrV1.30:rvnAcer:rnAspire5742G:rvrV1.30:cvnAcer:ct10:cvrV1.30:
dmi.product.family: Intel_Mobile
dmi.product.name: Aspire 5742G
dmi.product.sku: Calpella_CRB
dmi.product.version: V1.30
dmi.sys.vendor: Acer

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1912887/+subscriptions

--
Mailing list: https://launchpad.net/~kernel-packages
Post to : kernel-packages@lists.launchpad.net
Unsubscribe : https://launchpad.net/~kernel-packages
More help : https://help.launchpad.net/ListHelp

1 2 >

100 matches

Mail list logo