[systemd-devel] help : loginctl won't add new seat

[Benoit Barthelet]

long story short I had a working multiseat setup with 2 GPU / 2 mices
and 2 keyboards

I changed GPU drivers from open-source radeon to fglrx and it stopped working

before the driver change I had configured the 2nd seat to used the gpu
/ mice / keys with :

loginctl attach seat1
/sys/devices/pci0000:00/0000:00:01.0/0000:01:00.0/drm/card0/
etc..

the issue with the new drivers it seems is that I can't find the card0
in the /sys hierarchy,

for instance, it seems to be one of my card, but no seat tag :
udevadm info --query=all
--path=/sys/devices/pci0000:00/0000:00:07.0/0000:03:00.0

P: /devices/pci0000:00/0000:00:07.0/0000:03:00.0
E: DEVPATH=/devices/pci0000:00/0000:00:07.0/0000:03:00.0
E: DRIVER=fglrx_pci
E: ID_MODEL_FROM_DATABASE=Tahiti PRO [Radeon HD 7950/8950 OEM / R9 280]
E: ID_PCI_CLASS_FROM_DATABASE=Display controller
E: ID_PCI_INTERFACE_FROM_DATABASE=VGA controller
E: ID_PCI_SUBCLASS_FROM_DATABASE=VGA compatible controller
E: ID_VENDOR_FROM_DATABASE=Advanced Micro Devices, Inc. [AMD/ATI]
E: MODALIAS=pci:v00001002d0000679Asv0000174Bsd0000E207bc03sc00i00
E: PCI_CLASS=30000
E: PCI_ID=1002:679A
E: PCI_SLOT_NAME=0000:03:00.0
E: PCI_SUBSYS_ID=174B:E207
E: SUBSYSTEM=pci
E: USEC_INITIALIZED=4263516

So I tried to create manually a udev rule

/etc/udev/rules.d/71-ati.rules

SUBSYSTEM=="pci",
DEVPATH=="/devices/pci0000:00/0000:00:01.0/0000:01:00.0", TAG+="seat",
TAG+="master-of-seat"
SUBSYSTEM=="pci",
DEVPATH=="/devices/pci0000:00/0000:00:07.0/0000:03:00.0", TAG+="seat",
TAG+="seat1"

and now loginctl seat-status seat0 gives a master tag after udevadm trigger :
├─/sys/devices/pci0000:00/0000:00:01.0/0000:01:00.0
                  │ [MASTER] pci:0000:01:00.0

but I can never have a seat1, it never appears so the display manager
never tries to launch 2nd X session )

I'm at a loss here. any help appreciated