Bug#608616: Mobility Radeon HD 4200: Black screen after resuming from suspend / no-hibernation

[Michel Dänzer]

On Mon, 2011-01-03 at 09:15 -0300, Margarita Manterola wrote: 
> 
> > Let me get this straight: With the Debian driver package installed,
> > suspend/hibernation doesn't work no matter which kernel etc. you're
> > using. With the Ubuntu driver package installed, both work. And these
> > symptoms remain the same after switching back and forth between the
> > versions of the driver package. Did I get that right?
> 
> I tested it and this was right, after reverting everything back to squeeze,
> suspend/hibernate work fine.

Well, actually that wasn't what I meant, but it's good to clarify that
in any case. :)


> > KMS should be enabled by default in both cases, so colour me skeptical.
> > But you can try flipping it with the radeon kernel module parameter
> > 'modeset' to see if it makes any difference in either case.
> 
> It was set to 1.  I tried setting it to 0, and something new happened: both
> suspend and hibernate worked but when it came back it didn't show X, it
> showed some kernel messages, but doing Ctrl-Alt-F7 worked. I couldn't go
> back to those kernel messages afterwards.
>  
> Should I try setting it to something else?

No, this confirms that both KMS and UMS (can) work fine, thanks.


> So, I really don't know what's going on, but now it's a full squeeze system
> and it's working, when it was not working before... The only possible
> conclusion, except that I'm mad that I hope I'm not, is that some
> configuration was changed by ubuntu's packages that fixed the problem.

Can't think offhand of anything that could be other
than /etc/modprobe.d/radeon-kms.conf or /etc/X11/xorg.conf{,.d/*} ...

Could it be that it was a different kernel exhibiting the problems?

If not, I'm afraid I don't have any good ideas offhand how to figure out
what happened short of installing again and if the problem still occurs,
saving all even remotely relevant configuration and log files and then
looking for differences in them after the problem is fixed.


-- 
Earthling Michel Dänzer           |                http://www.vmware.com
Libre software enthusiast         |          Debian, X and DRI developer