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[Bug 1209008] Re: [SRU] X doesn't work for video cards with non-KMS drivers on non-seat0 seats


Does NOT work for me :-(

I'm still getting the "no screens found" error, which, if I understand correctly, is supposed to be fixed with:

$ cat /etc/apt/sources.list
deb http://archive.ubuntu.com/ubuntu/ trusty-proposed restricted main multiverse universe
deb http://pl.archive.ubuntu.com/ubuntu trusty-updates restricted universe main multiverse
deb http://security.ubuntu.com/ubuntu/ trusty-security restricted universe main multiverse
deb http://pl.archive.ubuntu.com/ubuntu trusty main restricted universe multiverse

$ dpkg -l xserver-xorg-core
ii  xserver-xorg-core                             2:1.15.1-0ubuntu2.6

$ lspci | grep VGA
01:00.0 VGA compatible controller: NVIDIA Corporation G98 [GeForce 8400 GS Rev. 2] (rev a1)
03:00.0 VGA compatible controller: NVIDIA Corporation G86 [Quadro NVS 290] (rev a1)

$ cat /etc/udev/rules.d/99-multiseat.rules
SUBSYSTEM=="drm", KERNEL=="card[0-9]*", ATTRS{vendor}=="0x10de", TAG+="master-of-seat"

TAG=="seat", DEVPATH=="/devices/pci0000:00/0000:00:01.0/0000:01:00.0/*", ENV{ID_SEAT}="seat0", TAG+="seat0"
TAG=="seat", DEVPATH=="/devices/pci0000:00/0000:00:1c.2/0000:03:00.0/*", ENV{ID_SEAT}="seat-1", TAG+="seat-1"

TAG=="seat", SUBSYSTEM=="usb", ATTR{name}=="DELL Dell USB Entry Keyboard", ENV{ID_SEAT}="seat0", TAG+="seat0"
TAG=="seat", SUBSYSTEM=="usb", ATTR{name}=="Logitech USB-PS/2 Optical Mouse", ENV{ID_SEAT}="seat0", TAG+="seat0"

TAG=="seat", SUBSYSTEM=="input", ATTR{name}=="AT Translated Set 2 keyboard", ENV{ID_SEAT}="seat-1", TAG+="seat-1"
TAG=="seat", SUBSYSTEM=="input", ATTR{name}=="ImPS/2 Generic Wheel Mouse", ENV{ID_SEAT}="seat-1", TAG+="seat-1"

$ loginctl list-seats

2 seats listed.

$ loginctl show-seat seat0

$ loginctl show-seat seat-1

$ loginctl list-sessions
   SESSION        UID USER             SEAT            
        c2       1000 andrzejtp        seat0           

1 sessions listed.

$ loginctl seat-status seat0
        Sessions: *c2
                   input:input1 "Power Button"
                   input:input0 "Power Button"
                   [MASTER] drm:card0
                   sound:card0 "Intel"
                   input:input10 "HDA Intel Line Out CLFE"
                   input:input11 "HDA Intel Line Out Side"
                   input:input12 "HDA Intel Front Headphone"
                   input:input5 "HDA Intel Rear Mic"
                   input:input6 "HDA Intel Front Mic"
                   input:input7 "HDA Intel Line"
                   input:input8 "HDA Intel Line Out Front"
                     input:input9 "HDA Intel Line Out Surround"
                   input:input13 "DELL Dell USB Entry Keyboard"
                     input:input14 "Logitech USB-PS/2 Optical Mouse"
                   video4linux:vbi0 "BT878 vbi ( *** UNKNOWN/GENERIC"
                   video4linux:video0 "BT878 video ( *** UNKNOWN/GENER"

$ loginctl seat-status seat-1
                   [MASTER] drm:card1
                   input:input2 "AT Translated Set 2 keyboard"
                    input:input4 "ImPS/2 Generic Wheel Mouse"

$ lsmod | grep nouveau
$ lsmod | grep nvidia 
nvidia               9704610  58 
drm                   244037  3 nvidia

$ cat /etc/lightdm/lightdm.conf 

# cat /var/log/lightdm/x-1.log

X.Org X Server 1.15.1
Release Date: 2014-04-13
X Protocol Version 11, Revision 0
Build Operating System: Linux 3.2.0-70-generic i686 Ubuntu
Current Operating System: Linux turbo 3.13.0-43-generic #72-Ubuntu SMP Mon Dec 8 19:35:44 UTC 2014 i686
Kernel command line: BOOT_IMAGE=/vmlinuz root=/dev/sda1 nomodeset
Build Date: 10 December 2014  06:16:10PM
xorg-server 2:1.15.1-0ubuntu2.6 (For technical support please see http://www.ubuntu.com/support) 
Current version of pixman: 0.30.2
	Before reporting problems, check http://wiki.x.org
	to make sure that you have the latest version.
Markers: (--) probed, (**) from config file, (==) default setting,
	(++) from command line, (!!) notice, (II) informational,
	(WW) warning, (EE) error, (NI) not implemented, (??) unknown.
(==) Log file: "/var/log/Xorg.1.log", Time: Sat Dec 13 19:25:33 2014
(==) Using system config directory "/usr/share/X11/xorg.conf.d"
Initializing built-in extension Generic Event Extension
Initializing built-in extension SHAPE
Initializing built-in extension MIT-SHM
Initializing built-in extension XInputExtension
Initializing built-in extension XTEST
Initializing built-in extension BIG-REQUESTS
Initializing built-in extension SYNC
Initializing built-in extension XKEYBOARD
Initializing built-in extension XC-MISC
Initializing built-in extension SECURITY
Initializing built-in extension XINERAMA
Initializing built-in extension XFIXES
Initializing built-in extension RENDER
Initializing built-in extension RANDR
Initializing built-in extension COMPOSITE
Initializing built-in extension DAMAGE
Initializing built-in extension MIT-SCREEN-SAVER
Initializing built-in extension DOUBLE-BUFFER
Initializing built-in extension RECORD
Initializing built-in extension DPMS
Initializing built-in extension Present
Initializing built-in extension DRI3
Initializing built-in extension X-Resource
Initializing built-in extension XVideo
Initializing built-in extension XVideo-MotionCompensation
Initializing built-in extension SELinux
Initializing built-in extension XFree86-VidModeExtension
Initializing built-in extension XFree86-DGA
Initializing built-in extension XFree86-DRI
Initializing built-in extension DRI2
Loading extension GLX
Fatal server error:
(EE) no screens found(EE) 
Please consult the The X.Org Foundation support 
	 at http://wiki.x.org
 for help. 
(EE) Please also check the log file at "/var/log/Xorg.1.log" for additional information.
(EE) Server terminated with error (1). Closing log file.

On the other hand, if I use nouveau, both seats come up, but once a demanding application (like firefox) is started at seat-1, screen quickly becomes full of garbage and in dmes I can see many lines like:
Dec 13 17:20:28 turbo kernel: [ 2788.000175] nouveau E[  PGRAPH][0000:03:00.0] ch 2 [0x000fb43000 Xorg[21316]] subc 0 class 0x0030 mthd 0x0224 data 0x00000140
Dec 13 17:20:28 turbo kernel: [ 2788.000193] nouveau E[  PGRAPH][0000:03:00.0]  ILLEGAL_MTHD.

To conclude this lengthy post: either I have both seats but one unusable
(with nouveau), or I have just one seat working properly while the other
gets "no screens found" (with nvidia).

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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:
  Fix Released
Status in xorg-server package in Ubuntu:
  Fix Released
Status in xorg-server source package in Trusty:
  Fix Committed

Bug description:

  * 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.

  Patch "xfree86_allow_fallback_to_pci_bus_probe_for_non_seat0.patch"
  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

  Section "Device"
      Identifier "card0"
      Driver "nvidia"
      Option "NoLogo" "True"
      # This section will only apply for seat-1
      MatchSeat "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.

  [Test Case]

  * 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.

  [Regression Potential]

  * Very low. All these patches were well tested in xorg-server "trusty"
  package available in ppa:ubuntu-multiseat/ppa.

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