@Christopher M. Penalver : > When you remove kernel parameter "acpi_backlight=vendor", what is the results > of executing at the Terminal: > ls /sys/class/backlight
When I remove it with latest Toshiba BIOS 2.20 (only 1 week old), my system makes a very long pause (about 1 minute) during boot, after displaying : [ 3.346332] [Firmware Bug]: ACPI(VGA) defines _DOD but not _DOS Then I get the output to your question: # cat /proc/cmdline BOOT_IMAGE=/vmlinuz-3.2.0-21-generic root=/dev/mapper/VG1-UBUNTU ro rdblacklist=nouveau nouveau.blacklist=1 clocksource=hpet rdblacklist=nouveau nouveau.blacklist=1 acpi_osi=Linux quiet splash vt.handoff=7 # ll /sys/class/backlight/ total 0 drwxr-xr-x 2 root root 0 avril 3 06:55 ./ drwxr-xr-x 50 root root 0 avril 3 06:55 ../ lrwxrwxrwx 1 root root 0 avril 3 07:00 toshiba -> ../../devices/LNXSYSTM:00/device:00/TOS1900:00/backlight/toshiba/ # ll /sys/class/backlight/toshiba/ total 0 drwxr-xr-x 3 root root 0 avril 3 06:56 ./ drwxr-xr-x 3 root root 0 avril 3 06:56 ../ -r--r--r-- 1 root root 4096 avril 3 07:01 actual_brightness -rw-r--r-- 1 root root 4096 avril 3 07:01 bl_power -rw-r--r-- 1 root root 4096 avril 3 07:01 brightness lrwxrwxrwx 1 root root 0 avril 3 07:01 device -> ../../../TOS1900:00/ -r--r--r-- 1 root root 4096 avril 3 07:01 max_brightness drwxr-xr-x 2 root root 0 avril 3 07:01 power/ lrwxrwxrwx 1 root root 0 avril 3 06:56 subsystem -> ../../../../../../class/backlight/ -r--r--r-- 1 root root 4096 avril 3 07:01 type -rw-r--r-- 1 root root 4096 avril 3 06:56 uevent > With "acpi_backlight=vendor" added, what is the result of executing at the > Terminal: > ls /sys/class/backlight # cat /proc/cmdline BOOT_IMAGE=/vmlinuz-3.2.0-21-generic root=/dev/mapper/VG1-UBUNTU ro rdblacklist=nouveau nouveau.blacklist=1 clocksource=hpet rdblacklist=nouveau nouveau.blacklist=1 acpi_osi=Linux acpi_backlight=vendor quiet splash vt.handoff=7 # ll /sys/class/backlight/ total 0 drwxr-xr-x 2 root root 0 avril 2 23:19 ./ drwxr-xr-x 50 root root 0 avril 2 23:19 ../ lrwxrwxrwx 1 root root 0 avril 2 23:22 toshiba -> ../../devices/LNXSYSTM:00/device:00/TOS1900:00/backlight/toshiba/ # ll /sys/class/backlight/toshiba/ total 0 drwxr-xr-x 3 root root 0 avril 2 23:20 ./ drwxr-xr-x 3 root root 0 avril 2 23:20 ../ -r--r--r-- 1 root root 4096 avril 3 06:50 actual_brightness -rw-r--r-- 1 root root 4096 avril 3 06:50 bl_power -rw-r--r-- 1 root root 4096 avril 2 23:22 brightness lrwxrwxrwx 1 root root 0 avril 3 06:50 device -> ../../../TOS1900:00/ -r--r--r-- 1 root root 4096 avril 2 23:22 max_brightness drwxr-xr-x 2 root root 0 avril 3 06:50 power/ lrwxrwxrwx 1 root root 0 avril 2 23:20 subsystem -> ../../../../../../class/backlight/ -r--r--r-- 1 root root 4096 avril 2 23:22 type -rw-r--r-- 1 root root 4096 avril 2 23:20 uevent > If you boot with kernel parameter acpi_osi="Linux" can you change your > backlight? No change, no help. > Could you please test the latest upstream kernel available? It will allow > additional upstream developers to examine the > issue. I won't be able to do this very soon, but doubt much it will help, the whole WWW being full of reports that backlight doesn't work on *many* NVidia equipped laptops... Furthermore, as an indication, I've found the nvidia-bl-dkms ( 0.17.3~natty) from http://ppa.launchpad.net/mactel-support/ppa/ubuntu (the whole web talks about it...) If I patch it so it recognizes my card PCI id, then compile it; when I modprobe it my backlight changes immediately to about 1/4 of its max value (visually). I then find myself having: # modprobe nvidia_bl # ll /sys/class/backlight/ total 0 drwxr-xr-x 2 root root 0 avril 2 23:19 ./ drwxr-xr-x 50 root root 0 avril 2 23:19 ../ lrwxrwxrwx 1 root root 0 avril 3 06:52 nvidia_backlight -> ../../devices/virtual/backlight/nvidia_backlight/ lrwxrwxrwx 1 root root 0 avril 2 23:22 toshiba -> ../../devices/LNXSYSTM:00/device:00/TOS1900:00/backlight/toshiba/ # ll /sys/class/backlight/nvidia_backlight/ total 0 drwxr-xr-x 3 root root 0 avril 3 06:52 ./ drwxr-xr-x 3 root root 0 avril 3 06:52 ../ -r--r--r-- 1 root root 4096 avril 3 06:52 actual_brightness -rw-r--r-- 1 root root 4096 avril 3 06:52 bl_power -rw-r--r-- 1 root root 4096 avril 3 06:52 " -r--r--r-- 1 root root 4096 avril 3 06:52 max_brightness drwxr-xr-x 2 root root 0 avril 3 06:52 power/ lrwxrwxrwx 1 root root 0 avril 3 06:52 subsystem -> ../../../../class/backlight/ -r--r--r-- 1 root root 4096 avril 3 06:52 type -rw-r--r-- 1 root root 4096 avril 3 06:52 uevent I note that if I then poke values into "brightness" there : - > 2047 : Error message "out of range" - >= 124 : No change (about 1/3 backlight) - < 123 : Backilght completely off - = 123 : Backlight flickers strangely So, event though this nvidia_bl module doesn't solve my problem completely, there's definitely something to look for in this direction (and I don't believe that just a latest upstream kernel install might help...)... Thanks for your help. ** Tags removed: needs-upstream-testing ** Changed in: linux (Ubuntu) Status: Incomplete => Confirmed -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/971750 Title: [Precise] Toshiba L735-101 screen brightness cannot be set using hotkeys To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/971750/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
