Re: [PATCH] i915: Quirk out disconnected backlight

From: Matthew Garrett
Date: Fri Sep 14 2012 - 10:40:46 EST

On Fri, Sep 14, 2012 at 03:29:14PM +0100, David Woodhouse wrote:
> On Fri, 2012-09-14 at 14:48 +0100, Matthew Garrett wrote:
> > On Fri, Sep 14, 2012 at 01:57:06PM +0100, Grant Likely wrote:
> >
> > > Tested on MacbookPro8,3. Without this patch both the intel_backlight and
> > > gmux_backlight devices get registered and userspace doesn't know which
> > > it should use.
> >
> > Userspace should be figuring out which one to use from the type field.
> It only does that if it's using gsd-backlight-helper to poke
> at /sys/class/backlight directly. If X exposes a backlight, (as it does
> for the Intel backlight), then gsd will just use that.

Yeah, X should be doing the same. If it's not then it's broken. OTOH, I
do agree that if we already know that we can't do anything with the
backlight (as is clearly the case if the PWM field is 0) we should just
disable it.

Matthew Garrett | mjg59@xxxxxxxxxxxxx
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at