Laptop Brightness Problem on Toshiba Portege R705-P35

Basic Specs:

• Toshiba Portege R705-P35
  • 13.1" screen
  • Intel HD Graphics
  • 4 GB RAM, Core i3 2.4 GHz
• Dual Boot Ubuntu 11.04 and Windows 7 (using grub bootloader)

Basically, Ubuntu recognizes me pressing the key combinations(Fn+F6 and Fn+F7) for changing my screen brightness and shows the notification bubble where the level changes. However this change isn't actually reflected on the screen. The brightness remains unchanged from what I left it at when I was logged into Windows. This problem has only manifested itself after I update to Natty, the brightness adjustment worked perfectly in 10.10 for me.

It seems I have the same issue as in this: Changing brightness on a Sony Vaio laptop question, however on a Toshiba Portege R705-P35. Even if I knew exactly what to do based on the top answer (yeah, no clue what to do inside the keymap rules), it doesn't seem to be the right thing to do since Ubuntu does recognize my keystrokes anyway.

Relevant, but doesn't solve the issue only presents a workaround:

Can't adjust brightness on my laptop

In 13.04, I found that /sys/class/backlight/toshiba breaks after suspend, but /sys/class/backlight/intel_backlight continues to function (echo $number > backlight after resume from suspend). Some great folks over at Arch have figured this one out. This does the trick:

Source: https://wiki.archlinux.org/index.php/Intel_Graphics#Backlight_not_fully_adjusting.2C_or_adjusting_at_all_after_resume.

Adapting this for Ubuntu 13.04:

1. sudo vi /etc/default/grub

2. change the line GRUB_CMDLINE_LINUX_DEFAULT as follows:

   GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor"
   

3. sudo update-grub

4. Configure X11 to use the intel_backlight. Create a file called 20-intel.conf here:

   sudo vi /usr/share/X11/xorg.conf.d/20-intel.conf
   

5. Paste in the following:

   Section "Device"
           Identifier "card0"
           Driver "intel"
           Option "Backlight" "intel_backlight"
           BusID "PCI:0:2:0"
   
   EndSection
   

6) Reboot and bask in glorious brightness control. Suspend/resume and it continues to function normally from the Fn-F6/F7 keys.

@keks-n (via Launchpad) is hosting a script at his/her PPA that automatically applies toshiba-acpi patch to your kernel. I think it even rebuilds DKMS style if you change kernel (?)

sudo apt-add-repository ppa:keks9n/main && sudo apt-get update && sudo apt-get install toshiba-acpi-fix

Check your toshset settings with:

sudo toshset -q

Full list of toggles:

sudo toshset

I've been running this patch for about a month, but the minor functionality gains (ability to adjust brightness after resume, disable bluetooth, kill backlight) appear to be offset by more frequent system hangs. At least that's my perception.

Apparently recent kernels are missing some support for toshiba acpi. There are various patches you can experiment with, discussed here: http://ubuntuforums.org/showthread.php?t=1550219