Re: regression since 2.6.36: backlight in sony-laptop not working

Zhang Rui
2010-11-12T07:37:27Z

On Fri, 2010-11-12 at 11:50 +0800, Norbert Preining wrote:
> On Fr, 12 Nov 2010, Matthew Garrett wrote:
> > > Seems so that the sys files have changed to new locations:
> > > /sys/devices/virtual/backlight/acpi_video0/brightness
> > >
> > > (mind the additional "virtual")
> > > as well as thermal zone etc etc.
> > >
I think the /sys/class/thermal/ and /sys/class/backlight/acpi_video0
still exists, right?

we make ACPI video procfs I/F depend on CONFIG_ACPI_PROCFS, which is
cleared by default, in 2.6.36, and removed this I/F in 2.6.37-rc1.
perhaps the backlight control depends on the procfs I/F?

thanks,
rui

> > > Could that explain the problem?
> >
> > Only if you have some wonderfully badly written software. What are you
> > using to control the backlight? Also, I'd note that in this case your
> > backlight is controlled via ACPI, not sony-laptop.
>
> Ah right, yes, so probabyl sony-laptopt has nothing to do with it.
>
> THen the problem is simply that the acpi events are not coming through
> when pressing the respective keys.
>
> But *that* might be part of the sony-laptop kernel module?
>
> Best wishes
>
> Norbert
> ------------------------------------------------------------------------
> Norbert Preining preining@{jaist.ac.jp, logic.at, debian.org}
> JAIST, Japan TeX Live & Debian Developer
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