On Wed, 2013-07-24 at 02:05 +0200, Rafael J. Wysocki wrote:
> On Tuesday, July 23, 2013 11:46:29 AM Kamal Mostafa wrote:
> > On Mon, 2013-07-22 at 21:54 +0200, Rafael J. Wysocki wrote:
> > > On Monday, July 22, 2013 11:11:54 AM Linus Torvalds wrote:
> > > > On Mon, Jul 22, 2013 at 6:02 AM, Rafael J. Wysocki <rjw@sisk.pl> wrote:
> > > > >
> > > > > Linus, do you want me to send a pull request reverting 8c5bd7a and efaa14c?
> > > > 
> > > > Yes, but [...] I'd suggest doing the revert just in time for
> > > > rc3, but waiting until then to gather info about people who see
> > > > breakage.
> > > > 
> > > > Sound like a plan?
> > > 
> > > Yes, it does.
> > > 
> > > Rafael
> > 
> > 
> > Hi Rafael-
> > 
> > For your reference...
> > 
> > As James Hogan reported, those ACPI changes break backlight control on
> > the "Dell XPS13" Ivy Bridge models (the Sandy Bridge XPS13 model is not
> > affected).
> > 
> > I confirm that reverting 8c5bd7a and efaa14c fixes it again.
> 
> Thanks!
> 
> I'd like to collect some information on the systems having problems with those
> two commits (to see if they are similar somehow).
> 
> It seems that one common symptom is that brightness cannot be controlled
> through function keys.  Is that correct for all of you?  If so, did you try
> any other way to control brightness, like a GUI-based?
> 
> Also, can you all please send me (a) the output of dmidecode and (b) the
> contents of /proc/cpuinfo from your systems?
> 
> Rafael
> 
> 

Attached.