Bug 10089

Summary:	no sysfs backlight interface on lifebook p7010
Product:	ACPI	Reporter:	Khashayar Naderehvandi (khashayar.lists)
Component:	Power-Video	Assignee:	Jonathan Woithe (jwoithe)
Status:	CLOSED INVALID
Severity:	normal	CC:	acpi-bugzilla, jwoithe
Priority:	P1
Hardware:	All
OS:	Linux
Kernel Version:	Any kernel version	Subsystem:
Regression:	---	Bisected commit-id:
Attachments:	output of dmidecode on lifebook p7010 output of acpidump output of dmesg

Description Khashayar Naderehvandi 2008-02-24 10:51:54 UTC

Latest working kernel version:
None

Distribution:
Any (I can perform tests and further debugging on Ubuntu 8.04, or possibly archlinux)

Hardware Environment:
Fujitsu-Siemens Lifebook p7010, intel 855GM.

Problem Description:

I first filed this bug at freedesktop against hal (http://bugs.freedesktop.org/show_bug.cgi?id=12638), but the hal guys suggested I take it over here. Basically, the problem is that hal cannot get/set backlight on my laptop since there is no sysfs interface to deal with that. Using Fn-F6/Fn-F7, I can manually change backlight.

lshal | grep panel

returns nothing. I'll attach the output of dmidecode.

Please give me more information on how to debug this issue. Many thanks!

Comment 1 Khashayar Naderehvandi 2008-02-24 10:52:55 UTC

Created attachment 14963 [details]
output of dmidecode on lifebook p7010

Comment 2 ykzhao 2008-02-25 18:05:10 UTC

Will you please attach the output of dmesg and acpidump?
Thanks.

Comment 3 Khashayar Naderehvandi 2008-02-26 08:30:32 UTC

Created attachment 15011 [details]
output of acpidump

Comment 4 Khashayar Naderehvandi 2008-02-26 08:31:23 UTC

Created attachment 15012 [details]
output of dmesg

Comment 5 Khashayar Naderehvandi 2008-02-26 08:32:12 UTC

I hope this helps.

Regards,
K.

Comment 6 Zhang Rui 2008-02-26 23:38:57 UTC

the fujitsu laptop doesn't follow the ACPI video extension, thus we need a platform specific driver to handle the backlight stuff via it's private control method.
Please set the CONFIG_FUJITSU_LAPTOP and see if it can work for you.
If not, it means that your laptop is not supported currently.

Comment 7 Zhang Rui 2008-02-26 23:41:29 UTC

Add the Jonathan Woithe in the cc list, who is the author of the fujitsu-laptop driver.

Comment 8 Khashayar Naderehvandi 2008-02-27 08:08:03 UTC

Thank you for pointing out CONFIG_FUJITSU_LAPTOP, I was not aware of this. 
I have now tried using this module, which results in a directory at /sys/devices/virtual/backlight/fujitsu-laptop populated with a few files.

taking a look at the files 'max_brightness' and 'actual_brightness' seems to reveal correct information about maximum and actual brightness respectively. However, actual_brightness is read only, and I have no idea how I could influence the brightness using this interface. Neither hal, or the xbacklight tool seem to be able to use this interface either. This is the list of files created:

actual_brightness
bl_power
brightness
max_brightness
power
subsystem
uevent

Comment 9 Khashayar Naderehvandi 2008-02-27 08:13:38 UTC

I'm sorry, I was too fast. 
It seems echoing to 'brightness' indeed sets brightness on my laptop.
I say we close this bug, and I'll continue with the freedesktop guys...

Comment 10 Jonathan Woithe 2008-02-27 14:20:37 UTC

Thanks for the confirmation that the driver works on your S7010.  This bug can be closed.