radeon/kms: screen goes black suddenly in multiseat configuration

[Eial Czerwacki <eial@scalemp.com>]

Hello All,

first I apologize for resending this mail, I've noticed I didn't
properly defined the header.

I have a two seat multiseat config using two gpus.
when I first boot the computer and starts to work with seat 0, after a
few minutes my screen goes black and it behaves like it went to sleep.

the system has two gpus, seat 1 uses an ati 5450HD at slot 1
(pcie2.0x16) and seat 0 uses an ati 3650HD at slot 6 (pciex4).

this only happens after cold reboot/power cycle, after I restart X (in
ssh, if I logon via the other seat and reboot it happens again), it
doesn't happens again.

also this doesn't occurs on seat 1 so I suspect it has to do with the
pci slot.

I've manually disabled DPMS in X but I don't think that is the issue.

I'm using kernel 3.1.1, my dmesg can be found at
http://pastebin.com/TZHvDWNe and my lspci can be found at
http://paste.pocoo.org/show/509652/

any ideas what can cause it?

Thanks

Eial.