[Bug 15166] Changing brightness of backlight freezes kernel with radeon kms enabled.

[bugzilla-daemon@bugzilla.kernel.org]

http://bugzilla.kernel.org/show_bug.cgi?id=15166





--- Comment #22 from Manuel Ullmann <ullman.bugs@gmx.de>  2010-02-09 20:58:17 ---
Created an attachment (id=24980)
 --> (http://bugzilla.kernel.org/attachment.cgi?id=24980)
syslog-ng output of an isuue caused by BIOS.

@Alex Deucher:

You mentioned earlier some 'scratch reg bits'. What are they doing? How could
they fix issues specific to certain systems like the Compaq 6735b series?
Your patch at
http://people.freedesktop.org/~agd5f/0001-drm-radeon-kms-add-additional-safe-regs-for-r4xx-rs.patch
seems to be related to those bits, but it is specific to some graphic chips.


I have experienced, that waking up from S3 or S4 can indeed change the
brightness with kms. As mentioned in Comment 12, the brightness uninitialized
until it is changed. /sys/class/backlight/acpi_video?/backlight has the value
0, although the backlight has full brightness, which should be 24. When
hibernate-script reinitializes the backlight, it is switched to its lowest
brightness. So I can choose now between the highest and lowest brightness. But
nevertheless the main issue, that the system freezes after certain amount of
inactivity, remains.

I understand, that the firmware is not likely to be updated and that instead
the kernel framework around it maybe has to be fixed. Of course this could be
also BIOS-related, as I had already an issue, which was caused by an error in
BIOS with this notebook (see attachement). But as this Bug is not
OS-independent, I doubt that it would be fixed ever.

-- 
Configure bugmail: http://bugzilla.kernel.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are watching the assignee of the bug.

------------------------------------------------------------------------------
SOLARIS 10 is the OS for Data Centers - provides features such as DTrace,
Predictive Self Healing and Award Winning ZFS. Get Solaris 10 NOW
http://p.sf.net/sfu/solaris-dev2dev
--