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Old 05-07-10, 02:23 PM   #56
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Join Date: May 2010
Posts: 1
Default Re: Linux backlight driver


Great Jobs! Thanks to your work, at last, now I can modify the backlight level on a Toshiba U500 with a g210m nvidia video. To do that, I had to add to the source code file nvidia_bl.c, PCI_VENDOR_ID_TOSHIBA in the struct "nvidia_bl_subvendors".
Also, in order to be compatible with power-manager, I create in /usr/modprobe.d folder
a nvidia_bl.conf file with the string "nvidia_bl max_level=0x7000 shift=8" in it. Indeed it seems that the maximum level is around 0x7000.

Finally, I used the trick of damdim with
<match key="linux.sysfs_path" string="/sys/devices/virtual/backlight/acpi_video0">
instead of
<match key="linux.sysfs_path" string="/sys/devices/virtual/backlight/sony">


PS. I made a confusion with the mactel version of the nvidia_bl.c source. The options are only valid for the mactel version. For people that wants to use the nvidia_bl driver (mactel or this one) be careful that in the /etc/X11/xorg.conf file, there is no the line 'Option "RegistryDwords" "EnableBrightnessControl=1"' in device section. Indeed, with this option the behaviour is quite strange, for low value, there is a crackling and the lightening is not uniform. Without this option, the maximum value seems to be equal to be 0x20000.

Last edited by julien321; 05-08-10 at 03:01 PM. Reason: corrections
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