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://ask
> > ub
> > 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.
