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

[Michel Dänzer]

On Sam, 2011-01-01 at 22:09 -0300, Margarita Manterola wrote: 
> 
> I'm working with an Asus EeePC 1215T, that comes with a Mobility Radeon HD
> 4200, after installing a fresh squeeze into it, suspend and hibernate
> didn't work properly: suspend worked, but when returning, no video
> returned, hibernation didn't work (black screen but no power off).
> 
> After installing the xserver driver from maverick (1:6.13.1-1ubuntu5), both
> started working properly.  So it seems that there's a difference in the
> patches applied in one and the other that makes suspension/hibernation work
> with one and not the other.

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?


> After looking at the changelogs and differences between the two packages, I
> have the sensation that the problem might be related to kms, but I really
> don't know enough about X to debug this myself.

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.


Otherwise, apart from any possible code differences between the driver
package versions (haven't checked yet), I assume that switching between
them also requires switching versions of other packages, in particular
xserver-xorg-core. The difference might actually be there. E.g. it might
be interesting rebuilding the Debian driver package against the Ubuntu X
server and vice versa and seeing what happens in each case.


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