could use help debugging black screen on RS780 (xf86-video-ati-6.13.0, radeon)

[Larry Doolittle]

Ross -

On Tue, Jun 01, 2010 at 10:09:21AM -0400, Ross Vandegrift wrote:
> On Mon, May 31, 2010 at 09:52:37PM -0700, Larry Doolittle wrote:
> > ... screens go black when I start the X server.
> 
> I've recently been seeing this symptom as well.  Same Debian release,
> ATI RS880 video.  Maybe 10% of the time, when returning from video
> suspend, the screen contents come up for approximately a second and
> then the monitor goes blank.  Switching to a text VT and back fixes
> the issue.
> 
> Only seems to be triggered on startup and return from power saving
> mode.

My black-screen is 100% reliable.  Maybe the underlying cause is
similar, but the symptoms sound different to me.  I never see
anything, not even for a second.  OTOH, maybe there is something
there for a second but my monitor doesn't sync to it in time.

Just for kicks, I installed the firmware-linux-nonfree package,
so the kernel could have those radeon microcode files if it wanted.
It didn't help.  I don't see the RS780 on the list of files at
  http://packages.debian.org/squeeze/firmware-linux-nonfree
except generically in the R700-family.

I only have access to this computer for a limited number of hours
in the day, so my debugging iterations may be slow.

I have assumed that the problem is in the hardware-dependent
xf86-video-ati-6.13.0 module.  Is there any point in trying
more recent versions of the X server itself?  Squeeze runs
xserver-xorg-core based on xorg-server_1.7.7 .

   - Larry