Bug 15162 - Changing backlight brightness doesn't work on Acer eMachines G725
Summary: Changing backlight brightness doesn't work on Acer eMachines G725
Status: CLOSED INSUFFICIENT_DATA
Alias: None
Product: ACPI
Classification: Unclassified
Component: BIOS (show other bugs)
Hardware: All Linux
: P1 normal
Assignee: Zhang Rui
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2010-01-28 18:15 UTC by Jani-Matti Hätinen
Modified: 2010-04-04 00:32 UTC (History)
2 users (show)

See Also:
Kernel Version: 2.6.32
Subsystem:
Regression: No
Bisected commit-id:

Attachments
dmidecode output (11.13 KB, application/octet-stream)
2010-01-28 18:15 UTC, Jani-Matti Hätinen 		Details
acpidump output (189.98 KB, application/octet-stream)
2010-01-28 18:15 UTC, Jani-Matti Hätinen 		Details
dmesg output (48.81 KB, text/plain)
2010-01-28 18:16 UTC, Jani-Matti Hätinen 		Details
Add an attachment (proposed patch, testcase, etc.)

Description Jani-Matti Hätinen 2010-01-28 18:15:12 UTC 
Created attachment 24760 [details]
dmidecode output

Changing the screen backlight brightness doesn't work on an Acer eMachines G725 laptop.

Keyboard shortcuts (Fn+Left, Fn+Right) don't work, /sys/class/backlight/ is empty and all brightness nodes in /proc/acpi/video/ report <not supported>.

When a keyboard shortcut is pressed I get the following ACPI error in dmesg:
ACPI: Failed to switch the brightness
Comment 1 Jani-Matti Hätinen 2010-01-28 18:15:51 UTC 
Created attachment 24761 [details]
acpidump output
Comment 2 Jani-Matti Hätinen 2010-01-28 18:16:12 UTC 
Created attachment 24762 [details]
dmesg output
Comment 3 Zhang Rui 2010-01-29 01:20:09 UTC 
Another BIOS that we can not intialize IGD OpeRegion arbitrarily.

please boot with kernel option "nomodeset" and attach the dmesg output.
Comment 4 Zhang Rui 2010-01-29 01:24:44 UTC 
please rebuild the kernel with CONFIG_ACPI_DEBUG=y, and then reboot with boot option "acpi.debug_level=0x04 acpi.debug_layer=0x10000000".

please attach the dmesg output when "nomodeset" is also used.
please attach the output of "grep . /proc/acpi/video/*/*/*" both with and without boot option "nomodeset".
Comment 5 Zhang Rui 2010-02-21 07:29:40 UTC 
ping...
Comment 6 Zhang Rui 2010-03-02 08:23:42 UTC 
close this bug as there is no response for more than a month.
Note You need to log in before you can comment on or make changes to this bug.