No Backlight Control for Toshiba Satellite

[JNH]

===== Graphics card information ======
01:05.0 VGA compatible controller: Advanced Micro Devices [AMD] nee ATI RS780MC [Mobility Radeon HD 3100 Graphics] (prog-if 00 [VGA controller])
 Subsystem: Toshiba America Info Systems Device ff6a
 Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
 Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
 Latency: 0
 Interrupt: pin A routed to IRQ 18
 Region 0: Memory at e0000000 (32-bit, prefetchable) [size=256M]
 Region 1: I/O ports at 6000 [size=256]
 Region 2: Memory at f6300000 (32-bit, non-prefetchable) [size=64K]
 Region 5: Memory at f6200000 (32-bit, non-prefetchable) [size=1M]
 Expansion ROM at <unassigned> [disabled]
 Capabilities: <access denied>
 Kernel driver in use: fglrx_pci
 Kernel modules: fglrx_updates, radeon

====== Other Info =======
LM version: Linux Mint 13
Kernel: 3.2.0-36-generic #57-Ubuntu
Laptop: Toshiba Satellite L305D-S5934
Frequency: Always, 100% of the time

====== Problem =======
I have no backlight control whatsoever for my laptop (it's always set at 100%). I've even tried "xbacklight -set 0" and "echo 0 > /sys/class/backlight/toshiba/brightness" (I've tried other numbers, too, with no avail). I have installed the ATI radeon driver (both that were listed in "restricted hardware"). I tried using the open source driver. I tried reinstalling bash (one suggestion in a forum) and I tried setting GRUB_CMDLINE_LINUX to "set timeout=-1 nomodeset acpi_backlight=vendor acpi_osi=Linux video.brightness_switch_enabled=1" in /etc/default/grub.

When I do use "xbacklight..." and "echo 0...", whenever I get the value back (by either xbacklight -get or cat [...]/brightness) I see the low value of 0.

So far nothing has worked. Any ideas? I might like to try a little hacking, too (I like to be a problem-solver instead of a complainer). Or is this AMD's problem (seeing how reputable AMD is with open source ;-P )?

Thank you.

[michael (macfu1701)]

toshiba satellite S875 w/ radeon hd 7600m GPU

same problem; not able to adjust backlight. its always on at 100% in mint 14.

i did make SOME headway. i was testing in ubuntu 12.04 and booted over to win8 [blech] where i uninstalled the toshiba f keys addition. that allowed ubuntu to adjust the brightness from the control panel but not from the f-keys. mint is so far not able to modify the backlight.

[terano (terano)]

I have the same problem

toshiba satellite C50-B-16T
Mint MATE 64bit (Rebecca 17.1) (and also with 32bit)

no restult with xbacklight
/sys/class/backlight/ is empty

volume keys (up,down,mute) do work fine (in my case they share F9, F10, F11)

How can I contribute to help fixing this problem?

[terano (terano)]

I found out that in my case:
- /sys/class/backlight/ is empty in Mint MATE 17.1, but does contain acpi_video0/ and intel_backlight/ in Mint Cinnamon and KDE 17.1 .
- for Cinnamon and KDE I had to add acpi_backlight=vendor to GRUB_CMDLINE_LINUX in order to be able to adjust the brightness level (this Toshiba needs intel_backlight/ instead of the default used acpi_video0/)

- however in all cases (Mate, Cinnamon and KDE) the function keys for brightness control on my Toshiba Satellite C50-B (Fn+F2/F3) aren't recognized. Instead they have the function "Power Information" (F2) or "hibernate" (F3).

- I also like to mention that in keyboard preferences, there is only 1 Toshiba-model (satellite 3000) listed. finally for me best fit is the Generic 105-keys keyboard. I don't know how the development works, I can only guess that there is something wrong in the automatic detection of key-functions. (they seem to be mixed up: Power Information and Hibernate are misconnected to the brightness keys). Probably with several Toshiba Satellite-models and there is also a difference between MATE and Cinnamon/KDE. The last does recognize the available backlight function, but can't connect this to the right keyboard keys. MATE seems to detect nothing at all.

For me the solution is using Cinnamon on this laptop instead of MATE and accepting that the brightness-keys don't work.

Althought I didn't solve the initial post of JNH I hope my reaction is usefull to someone.

[Cedric Maunier (cedric.maunier)]

Hi,

Did you tried to install xbacklight ?

if yes, try this : it worked for me ;)

Open your /etc/default/grub with your text editor

for example :
sudo nano /etc/default/grub

Then, modify the line
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
by
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor"

then reboot...