Re: [PATCH] toshiba_acpi: fingers off backlight if video.ko is serving this functionality

Andrey Borzenkov
2008-11-15T18:42:25Z

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On Saturday 15 November 2008, Matthew Garrett wrote:
> On Sat, Nov 15, 2008 at 08:17:52PM +0300, Andrey Borzenkov wrote:
> > On Saturday 15 November 2008, Matthew Garrett wrote:
> > > > If you think exposing both knobs is non-issue, why are all those patches
> > > > for other vendor drivers included in the kernel in the first place?
> > >
> > > Because in some of those cases, the ACPI and vendor function are
> > > implemented in different ways that can then get out of sync with each
> > > other. As a result, you can get garbage information. If the values in
> > > your two backlight interfaces are always sane, then there's no inherent
> > > need to hide one of them.
> >
> > THE VALUE IN MY TWO BACKLIGHT INTERFACES ARE NOT THE SAME. I said this many
> > times already. What exactly is not clear in this sentence?
>
> Where did I say that they were? You never answered the question I asked
> - if you set the value in the toshiba specific backlight control to a
> value that isn't supported via the generic acpi one, what value does the
> generic acpi one claim to have?
>

sh-3.2# cat /sys/class/backlight/acpi_video0/brightness
2
sh-3.2# cat /sys/class/backlight/acpi_video0/actual_brightness
2
sh-3.2# cat /sys/class/backlight/acpi_video0/max_brightness
2
sh-3.2# cat /sys/class/backlight/toshiba/brightness
7
sh-3.2# cat /sys/class/backlight/toshiba/actual_brightness
7
sh-3.2# cat /sys/class/backlight/toshiba/max_brightness
7
sh-3.2# echo 5 > /sys/class/backlight/toshiba/brightnes
sh-3.2# cat /sys/class/backlight/acpi_video0/brightness
2
sh-3.2# cat /sys/class/backlight/acpi_video0/actual_brightness
2
sh-3.2# echo 5 > /sys/class/backlight/acpi_video0/brightness
sh: echo: write error: Invalid argument
sh-3.2# echo 1 > /sys/class/backlight/acpi_video0/brightness
sh-3.2# cat /sys/class/backlight/toshiba/brightness
5
sh-3.2# cat /sys/class/backlight/toshiba/actual_brightness
3
sh-3.2# echo 7 > /sys/class/backlight/toshiba/brightness
sh-3.2# cat /sys/class/backlight/acpi_video0/brightness
1
sh-3.2# cat /sys/class/backlight/acpi_video0/actual_brightness
1

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