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Re: Call for Testing: Updated Apple backlight driver

 

On Tue, Jan 31, 2012 at 09:52:39AM -0800, Colin D Bennett wrote:
> On Tue, 31 Jan 2012 11:35:16 -0600
> Seth Forshee <seth.forshee@xxxxxxxxxxxxx> wrote:
> 
> > > I updated the wiki page with results from my MacBookPro5,1.
> > > My backlight was working before, with stock Oneiric system, so
> > > I am testing just to make sure the new driver *still* works.
> > 
> > Thanks, Colin! I want testing for both machines that do and don't
> > have working backlights currently, so this is very helpful.
> > 
> > > Note that I have no acpi_video device, although the wiki page
> > > says I should have it at a minimum:
> > > 
> > >     $ ls /sys/class/backlight
> > >     gmux_backlight
> > 
> > Hmm. If that's the only device you have then I don't understand
> > how you could have had working brightness adjustments previously.
> > What devices are present if you uninstall the test driver?
> > 
> > Also, you aren't booting with acpi_backlight=vendor, are you? If
> > you are it will show up in /proc/cmdline.
> 
> Here are the results with the stock Ubuntu driver:
> 
>     $ cat /proc/cmdline 
>     BOOT_IMAGE=/vmlinuz-3.0.0-15-generic root=UUID=53f14c91-bf33-48ed-8845-faf445081024 ro quiet splash vt.handoff=7
>     $ ls /sys/class/backlight/
>     apple_backlight
>     $ ls /sys/class/backlight/apple_backlight
>     actual_brightness  brightness      power      type
>     bl_power           max_brightness  subsystem  uevent
>     $ cat /sys/class/backlight/apple_backlight/max_brightness 
>     15

Okay, the driver changes aren't intended to affect apple_backlight. The
changes must have had an unintentional impact on this. I'll look into it
and follow up with you off-list to get it resolved.

> > > Backlight adjustment through this gmux_backlight 'brightness'
> > > file works.  My backlight keys on the keyboard don't work,
> > > however, so I assume other changes are required to hook that up
> > > to the new backlight driver.
> > 
> > This is for the display backlight only. The keyboard backlight is
> > a completely different driver.
> 
> Sorry, I don't mean the 'keyboard backlight', but the F1/F2
> special function brightness keys on the laptop keyboard that are
> shortcuts for changing LCD backlight brightness. The on-screen
> display pops up but nothing happens when the keys are pressed,
> just as if I rmmod the apple_bl module.

My mistake, I misread your comment.

So if I understand correctly the keys work to adjust your backlight in
stock Oneiric but not with the test driver. Yeah, there might be some
work needed to get the new interface wired up. Although on a MacBook Pro
8,2 running Precise I haven't had to do anything special (other than
passing acpi_backlight=vendor to get rid of the nonfunctional
acpi_video0 backlight device).

Seth


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