hald-linux: LP #125918: keyboard backlight broken on new macbooks

Henrik Rydberg rydberg at euromail.se
Thu Oct 16 11:23:19 UTC 2008


Hello,

As described in LP #125918, the keyboard backlight cannot be controlled
via hotkeys on the recent macbooks. The bug reports seem to describe
several different problems, but it all boils down to a few problems:

1. In intrepid, hal is handling the keyboard backlight keys,
and pommed stops working.

2. If trying to make HAL actually handle the keyboard backlight, by adding
the recent macbooks to /usr/share/hal/fdi/policy/10osvendor/10-macbookpro-utils.fdi,
it will not work, because the hald-addon-macbookpro-backlight started off as
a handler for the LCD backlight of ATI X1600, and later got to handler also
the keyboard backlight and light sensors. Since the graphics handling is
different between the macbook models, this functionality is completely broken.

I sent three patches to HAL upstream a while ago, which adresses these problems.
The patches, which are attached to the LP bug, basically

1. Break out the keyboard_backlight and light_sensor functionality

2. Use the sysfs interface, rather than the apple smc interface implementation
used in hald-addon-macbookpro-backlight, which does not work properly on newer
macbooks

With little knowledge about the internal workings of hal, I simply created a
generic addon for the keyboard_backlight, which reads and writes to the sysfs
interface. There might be more elegant solutions to this particular part.
Using this addon, it is easy to remap the functionality via fdi. Analogously,
one could create an interface for the light_sensor, and that might come in a
second wave if these patches get accepted.

I have heard nothing from the hal mailing list. I would appreciate it if someone
would review and/or apply the patches at least to the ubuntu tree, so that this
bug can be solved.

Best regards,
Henrik Rydberg







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