Arch Linux

pingpong

Member

From: Los Angeles

Registered: 2010-12-30

Posts: 104

ACPI: Failed to switch the brightness

Just installed Arch on a Toshiba R835.

Fn 6 and Fn 7 fails to change the brightness of the LCD. It complaints
ACPI: Failed to switch the brightness

checked that toshiba_acpi loaded.

tried: https://bbs.archlinux.org/viewtopic.php?id=76799 and https://bbs.archlinux.org/viewtopic.php?id=73889
without any success. Also tried asking the question on the laptop forum but doesn't seem anyone get an idea. Perhaps, I posted it on a wrong forum so I'm trying this one.

The hotkey works in Gnome 3, more specifically gnome-power-manager
However, I don't need gnome.

Want: a solution without installing gnome. Any help?

axper

Member

Registered: 2013-01-25

Posts: 115

Re: ACPI: Failed to switch the brightness

I have exactly same problem.

Can bypass the issue by:
1) Echoing a value into /sys/class/backlight/intel_backlight/brightness
2) Using xbacklight
3) Using Gnome 3 desktop environment
None of those are acceptable solutions.

Tried everything I could find in these forums:
1) Creating file /etc/modprobe.d/video.conf, put "options video brightness_switch_enabled=1" into it and rebooting
2) Changing this line in /etc/default/grub, doing "grub-mkconfig -o /boot/grub/grub.cfg" and rebooting

GRUB_CMDLINE_LINUX="acpi_osi=\"!Windows 2012\" acpi_backlight=vendor ACPI_VIDEO=y VIDEO_OUTPUT_CONTROL=y clocksource=\"acpi_pm\""

Note: With ACPI_VIDEO and VIDEO_OUTPUT_CONTROL parameters there there is no error in dmesg, but I still cannot change brightness
Also tried acpi_osi=Linux

I have:
Lenovo B570e laptop
Intel HD Graphics card, i915 driver
i3 window manager

Various command outputs:
#lspci:

...
00:02.0 VGA compatible controller: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller (rev 09) (prog-if 00 [VGA controller])
        Subsystem: Lenovo Device 3975
        Flags: bus master, fast devsel, latency 0, IRQ 40
        Memory at d0000000 (64-bit, non-prefetchable) [size=4M]
        Memory at c0000000 (64-bit, prefetchable) [size=256M]
        I/O ports at 3000 [size=64]
        Expansion ROM at <unassigned> [disabled]
        Capabilities: [90] MSI: Enable+ Count=1/1 Maskable- 64bit-
        Capabilities: [d0] Power Management version 2
        Capabilities: [a4] PCI Advanced Features
        Kernel driver in use: i915
        Kernel modules: i915
...

dmesg | grep DMI

[    0.000000] DMI: LENOVO HuronRiver Platform/Emerald Lake, BIOS 44CN43WW 10/27/2011
[   18.520426] input: HDA Intel PCH HDMI/DP,pcm=3 as /devices/pci0000:00/0000:00:1b.0/sound/card0/input10

#dmidecode | grep "BIOS Rev"

	BIOS Revision: 1.67

defer

Member

From: Finland

Registered: 2013-06-25

Posts: 46

Website

Re: ACPI: Failed to switch the brightness

Im having this same problem on thinkpad E531.

---

https://github.com/defer-

axper

Member

Registered: 2013-01-25

Posts: 115

Re: ACPI: Failed to switch the brightness

Im having this same problem on thinkpad E531.

Does it react when you echo a number to /sys/class/backlight/intel_backlight/brightness ?