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

[bugzilla-daemon@bugzilla.kernel.org]

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

           Summary: Changing brightness of backlight freezes kernel with
                    radeon kms enabled.
           Product: Drivers
           Version: 2.5
    Kernel Version: 2.6.32.6
          Platform: All
        OS/Version: Linux
              Tree: Mainline
            Status: NEW
          Severity: high
          Priority: P1
         Component: Video(DRI - non Intel)
        AssignedTo: drivers_video-dri@kernel-bugs.osdl.org
        ReportedBy: ullman.bugs@gmx.de
        Regression: No


Created an attachment (id=24769)
 --> (http://bugzilla.kernel.org/attachment.cgi?id=24769)
Xorg-log from a normal X startup.

Overview:

Changing the brightness of the backlight freezes the kernel, when radeon kms
(radeon.modeset=1) is enabled. Closing the LID for ca. 5 minutes does the same.

There are several ways to reproduce this:

1.

Step 1: Become root and enter the following:
echo 90 | dd of=/proc/acpi/video/*/LCD/brightness
The system should freeze.

2.

Step 1: If you have a laptop, you can close your LID and wait ca. 5 min. When
you open it, you shouldn´t get your screen on.

3.

Step 1: If you have KDE 4 with powerdevil installed, simply type: startx
I guess, the system freezes when powerdevil tries to get control about the
backlight.

Actual Results:

The system freezes.

Expected Results:

Changing the brightness should work. Switching on the monitor should work.

Build Date and Platform:

Build 2010-01-25 on Gentoo Linux 10.0

Additional Builds and Platforms:

Occurs also with Gentoo-kernel 2.6.32-gentoo-r2

Additional Information:

Hardware:

HP Compaq 6735b (FU308EA)
(Radeon HD 3200)

See also:
http://h10010.www1.hp.com/wwpc/uk/en/sm/WF06b/321957-321957-64295-3955547-3955547-3687779-3840808.html

Userspace-drivers were compiled from Gentoo x11-overlay.

The symptoms of the freeze are very similar to those of a kernel panic:

- MAGIC_SYSRQ is not working.
- New USB-devices are not powered.
- Mouse freezes.
- In console the cursor is disappearing.

But:

- Num Lock and Caps Lock LED are not blinking
- Caps Lock LED does not glow.

I could not boot the 2.6.33-rc5-kernel, because amd-ucode was missing. I will
fix it and test this version later.

I´ll attach Xorg-log.

-- 
Configure bugmail: http://bugzilla.kernel.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are watching the assignee of the bug.
------------------------------------------------------------------------------
The Planet: dedicated and managed hosting, cloud storage, colocation
Stay online with enterprise data centers and the best network in the business
Choose flexible plans and management services without long-term contracts
Personal 24x7 support from experience hosting pros just a phone call away.
http://p.sf.net/sfu/theplanet-com
--
_______________________________________________
Dri-devel mailing list
Dri-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/dri-devel