Bug#587014: screen brightness can't be modified on some Panasonic laptops
A solution for this problem that works for me (ubuntu 10.10, 2.6.35-24 kernel) is described here http://ubuntuforums.org/showthread.php?t=1612560 In a nutshell, add the boot option acpi_osi= to grub, by executing $ gksudo gedit /etc/default/grub (which calls an editor) to replace in the file /etc/default/grub the line GRUB_CMDLINE_LINUX_DEFAULT=quiet splash with GRUB_CMDLINE_LINUX_DEFAULT=quiet splash acpi_osi= Then execute $ sudo update-grub and reboot. Backlight-changing should now work seamlessly. Axel -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Bug#587014: screen brightness can't be modified on some Panasonic laptops
On Wednesday 29 December 2010 16:24:28 Nicolas Limare wrote: I also received a message reportin for this bug on a Panasonic CF-52. Can I in any way help this bug get more attention? What is Bug#587014? Do you have a link? Panasonic is the only driver which will always try to use native backlight switching (may conflict with video.ko?). drivers/platform/x86/panasonic-laptop.c misses a line like: if (acpi_video_backlight_support() The reason panasonic was not changed to differ acpi/native switching was because ACPI based switching resulted in 2 missing backlight states. But this was fixed by better (more Windows compatible) parsing the backlight ACPI states and they should be all availeable with ACPI as well. Len Brown has/had such a machine. Just in case, I am at 27C3 now, with my laptop, so if anyone there wants to directly investigate the issue just let me know. No idea whether it's above, there is not much info about the issue, but you could try in this direction. Tell me if it helps or if you need assistance to try things out. Ah, and there is the global methods execution is broken: https://bugzilla.kernel.org/show_bug.cgi?id=19462 which very much affects Panasonics. Make sure your kernel has the git commit mentioned in the last comment. Thomas -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Bug#587014: screen brightness can't be modified on some Panasonic laptops
On Mon, Jan 03, 2011 at 10:40:03AM +0100, Thomas Renninger wrote: On Wednesday 29 December 2010 16:24:28 Nicolas Limare wrote: I also received a message reportin for this bug on a Panasonic CF-52. Can I in any way help this bug get more attention? What is Bug#587014? Do you have a link? Debian bug report #587014 - http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=587014 Linked to the Ubuntu bug report #588983 - https://bugs.launchpad.net/ubuntu/+source/linux/+bug/588983 Thanks a lot for your help Thomas. I can't confirm your diagnostics, because I'm not in a position to recompile the kernel, but hopefully these hints will help others resolve this bug. -- Nicolas LIMARE http://nicolas.limare.net/ pgp:0xFA423F4F signature.asc Description: Digital signature
Bug#587014: screen brightness can't be modified on some Panasonic laptops
No, there is no. Only the /sys/class/backlight/panasonic/ directory is present. Cristopher On Tue, Jan 4, 2011 at 5:33 AM, Matthew Garrett mj...@srcf.ucam.org wrote: Is there a /sys/class/backlight/acpi_video0 directory as well as the Panasonic one? -- Matthew Garrett | mj...@srcf.ucam.org -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Bug#587014: screen brightness can't be modified on some Panasonic laptops
Is there a /sys/class/backlight/acpi_video0 directory as well as the Panasonic one? -- Matthew Garrett | mj...@srcf.ucam.org -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Bug#587014: screen brightness can't be modified on some Panasonic laptops
On Tue, Jan 04, 2011 at 06:14:40AM +0800, Cristopher Camacho wrote: No, there is no. Only the /sys/class/backlight/panasonic/ directory is present. Can you attach the output of the acpidump command on your system? -- Matthew Garrett | mj...@srcf.ucam.org -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Bug#587014: screen brightness can't be modified on some Panasonic laptops
Well, that's odd. There's certainly support for ACPI backlight control in your firmware, and it goes via opregion so it should work correctly. I think the thing to do here is to have the panasonic driver bail if there's ACPI backlight support, and then figure out why the ACPI video driver isn't working for you. -- Matthew Garrett | mj...@srcf.ucam.org -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Bug#587014: screen brightness can't be modified on some Panasonic laptops)
The latest squeeze kernel (2.6.32-29) improved the situation. Now, when the system boots, the backlight is not automatically set to its maximum level. So, it is possible to set the backlight level during the BIOS boot phase, and keep this level. This is a big improvement since now the system is usable in a dark environment, even is adjusting the backlight level requires a reboot. Hotkeys still dont't work, and result in the following message in the system console: ACPI: Failed to switch the brightness Playing with /sys/class/backlight/panasonic/brightness doewsn't work either. -- Nicolas LIMARE http://nicolas.limare.net/ pgp:0xFA423F4F signature.asc Description: Digital signature
Bug#587014: screen brightness can't be modified on some Panasonic laptops
I also received a message reportin for this bug on a Panasonic CF-52. Can I in any way help this bug get more attention? Just in case, I am at 27C3 now, with my laptop, so if anyone there wants to directly investigate the issue just let me know. -- Nicolas LIMARE http://nicolas.limare.net/ pgp:0xFA423F4F signature.asc Description: Digital signature
