On Thu, 2016-06-23 at 15:32 -0600, James Lay wrote:
> On Thu, 2016-06-23 at 20:36 +0200, Sven Arvidsson wrote:
> > On Thu, 2016-06-23 at 10:42 -0600, James Lay wrote:
> > >
> > > Hey all,
> > >
> > > so....I have an oldish iMac 24 inch. It comes with a Radeon
> > > Mobility
> > > HD 4850. After install of Stretch testing, this worked fine,
> > > save
> > > for
> > > one small issue of the backlight not going out. As I run this as
> > > kind
> > > of a server with no need to see the screen most of the time, I'd
> > > like
> > > to get the backlight to go out. So I installed firmware-linux-
> > > nonfree.
> > > This actually causes me to get a blank screen...just the
> > > backlight
> > > on.
> > > I can ssh into the machine, but I get no screen at all (http://a
> > > skub
> > > un
> > > tu.com/questions/688388/14-04-gets-black-screen-unless-radeon-
> > > modeset-0
> > > ). I DO however see the backlight go out. Right now I'm using
> > > radeon.modeset=0 to get an active screen again. My question is
> > > there
> > > any way I can troubleshoot getting the backlight to go out? I've
> > > got
> > > to:
> > I found some old reports about video output being redirected to the
> > external display, that might be something to investigate?
> >
> > You don't run X at all? If so I'm not quite sure of to check for
> > which
> > display is active or how to control backlight.
> >
> Thanks for the quick response. This currently is running X, but only
> with radeon.modeset=0 for kernel args. Otherwise, the machine boots,
> just black screen.
>
>
>
And after hooking up a second monitor it indeeds defaults to that
second monitor after running:
modprobe radeon modeset=1
Now..I do I tell the driver which monitor to use? Thank you.
