Re: i915 backlight

From: Aaron Lu
Date: Wed Jul 31 2013 - 21:12:53 EST

On 08/01/2013 12:36 AM, Borislav Petkov wrote:
> On Wed, Jul 31, 2013 at 06:22:52PM +0200, Borislav Petkov wrote:
>> Dudes,
>> has anyone already reported this (happens on Linus of today +
>> tip/master):
> Oh, one more thing: I can't control the backlight anymore on this x230
> with the Fn-Fx keys and this is most probably related to that recent
> backlight revert story. If there is a new approach I can test, please
> let me know.

Can you please run acpi_listen and then press the Fn-Fx key, see if the
events are correctly sent out?

> Btw, it worked before on this machine with "acpi_backlight=vendor" on
> the cmdline.

>From the bug page:
I got the impression that both the acpi_video interface and the vendor
interface thinkpad_screen are broken. So adding this cmdline here works
suggests that either thinkpad_screen works or thinkpad vendor driver
doesn't get loaded or doesn't create that interface for some reason.

Alternatively, if the intel_backlight interface works(highly possible),
you can use xorg.conf to specify the that backlight interface for X.

Section "Device"
Option "Backlight" "intel_backlight"
Identifier "Card0"
Driver "intel"
BusID "PCI:0:2:0"

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