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[Bug 1209008] Re: [SRU] X doesn't work for video cards with non-KMS drivers on non-seat0 seats
Unfortunately, I can't reproduce your error in my hardware. Both seats
wake up correctly here.
My hardware consists of an integrated Intel graphics device and a
Silicon Motion SM501 PCI graphics card. I'm also using Xubuntu with
lightdm 1.10.3 from trust-updates repo.
BTW, did you upgrade your lightdm to 1.10.3? Dou you know this version
has backported automatic multiseat feature introduced in 1.12 series?
Although this is the default behaviour in 1.12 series, it must be
enabled manually in 1.10.3. Just drop all your previous manual seat
configurations ([Seat:0], [Seat:1], etc.) in lightdm.conf and put the
If you want to seat e.g. autologin user for each seat, just append the
autologin-user=<USER FOR seat0>
autologin-user=<USER FOR seat-1>
Now you can test again that setting above for disabling DPMS for your
seat-1 X server:
xserver-command=/usr/bin/X -core -dpms -s 0
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[SRU] X doesn't work for video cards with non-KMS drivers on non-seat0
Status in X.Org X server:
Status in xorg-server package in Ubuntu:
Status in xorg-server source package in Trusty:
* In Xorg-server versions older than 1.16, if Xorg is started as a
non-seat0 X server (i.e. if it was started with "-seat XXXX" option
where "XXXX" != "seat0"), it only probes platform bus for graphics
devices, leaving devices with non-KMS drivers (like NVIDIA proprietary
drivers and old ones like xf86-video-siliconmotion) unreachable.
from lp:~ubuntu-multiseat/xorg-server/trusty-matchseat fixes this.
* systemd-logind has no intrinsic mechanism to assign non-KMS graphics
devices to seats. In this case, one should tag another seat device
(keyboard, USB hub, etc.) in udev as "master-of-seat", and provide a
suitable xorg.conf for that seat. In order to avoid that a given
xorg.conf affects other seats, it should be passed to Xorg via
"-config xorg.conf.custom" option, which requires X server command
line customization support in DM in use (GDM, for example, has no such
Patch "xfree86_add_matchseat_key_to_xorg_conf.patch" from lp:~ubuntu-
multiseat/xorg-server/trusty-matchseat introduces a new MatchSeat key
for xorg.conf sections "Device", "Screen", and "ServerLayout", which
will target a given seat only. Example file
Option "NoLogo" "True"
# This section will only apply for seat-1
* systemd-logind can't handle any VT switching for non-seat0 seats,
but Xorg-server older than 1.16 still opens VT even if it's started as
a non-seat0 X server. This may lead to a race condition between X
servers: if a non-seat0 one is started before a seat0 one, the former
"steals" VTs from the later. If a seat0 X server can't open VTs,
systemd-logind can't activate sessions for seat0, leaving user without
sound or usb input support, for example.
Patch "xfree86_keep_non_seat0_from_touching_vts.patch" from lp
:~ubuntu-multiseat/xorg-server/trusty-matchseat fixes this.
* Set up a multiseat system where your non-seat0 seats use non-KMS
video drivers (you may need to tag another device in udev as "master-
of-seat" in order to achieve it).
* When LightDM/GDM tries to start a Xorg server for your non-seat0
seats, it will end up with the following error: "(EE) No devices
* After applying
xfree86_allow_fallback_to_pci_bus_probe_for_non_seat0.patch, you can
configure your seats in LightDM by setting appropriate "xserver-
config" properties for each seat. However, you can't configure them in
* After applying xfree86_add_matchseat_key_to_xorg_conf.patch,
configure your seats properly and restart LightDM/GDM services (or
reboot your computer) repeatedly. In some iterations, it may happen
that logind can't activate graphical sessions for seat0. If it occurs,
check output of command "ps -FC Xorg" and you'll see that a non-seat0
Xorg server has a lower PID than seat0 one. Moreover, the non-seat0
has opened a TTY, while the seat0 hasn't.
* Very low. All these patches were well tested in xorg-server "trusty"
package available in ppa:ubuntu-multiseat/ppa.
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