Silicon Motion X driver fails to correctly restore text mode; requires modprobe vga16fb fbcon

I should have noted that I'm aware vesafb is compiled into the kernel. For some reason, no matter what combination of modes are put on the kernel command-line, it doesn't help the virtual consoles.

With just vesafb+fbcon I tried vga=0x317 (1024 x 768 x 16) and 0x318 (1024 x 768 x 24) and they both worked whilst the system was starting up.

Another issue, possibly related, is that the initial GDM greeter screen is terribly colour-inverted (dark blue, negative-looking image). This is cured by switching away from VT7 and then switching back.

No, that's not the problem. vgacon is statically linked in. We deliberately don't use vga16fb or vesafb by default.

On Sun, 2007-09-23 at 14:54 +0000, Matthew Garrett wrote:
> No, that's not the problem. vgacon is statically linked in. We
> deliberately don't use vga16fb or vesafb by default.

vesafb+vgacon is ok during start-up but as soon as a graphics mode has
been activated (usplash or xorg) there is no VT console display.

With one of the VT consoles activated (by Ctrl+Alt+F1) all that is
apparent is the back-light glow.

Connecting via ssh from a remote PC and simply doing:

$ lsmod | egrep 'vga|fb'
fbcon 41760 72
tileblit 3584 1 fbcon
font 9344 1 fbcon
bitblit 6912 1 fbcon

$ sudo modprobe vga16fb

and the VT console text display instantly appears.

$ lsmod | egrep 'vga|fb'
vga16fb 15500 1
vgastate 11008 1 vga16fb
fbcon 41760 71
tileblit 3584 1 fbcon
font 9344 1 fbcon
bitblit 6912 1 fbcon

This might be related to the other Silicon Motion issue I've found in bug #144182 "Gutsy - Silicon Motion video driver freezes, corruption, and error reports".

>From a remote ssh session, whilst at the GDM greeter page:

tj@etch-a-sketch:~$ sudo vbetool vbemode get
3

After switching to VT console 1 using Ctrl+Alt+F1:

tj@etch-a-sketch:~$ sudo vbetool vbemode get
3
tj@etch-a-sketch:~$ lsmod | egrep 'vga|fb'
fbcon 41760 0
tileblit 3584 1 fbcon
font 9344 1 fbcon
bitblit 6912 1 fbcon

Do:

tj@etch-a-sketch:~$ sudo modprobe vga16fb

and text display appears.

tj@etch-a-sketch:~$ sudo vbetool vbemode get
3

I'm attaching the binary vbestate saved during boot-time in case it is of use.

It seems something there is something fundamentally wrong/broken. I have a Acer C100 TabletPC with SM720 lynx3dm silicon motion chipset. First I installed the final Ubuntu 8.10 where installation was running well until the reboot and where the gdm login should be there was just a blank screen. I gave xubuntu a try and installed Xubuntu 8.10 - same result everything fine until login screen (black but the system is normally running ctrl+alt+del brings the system down).

Interesting the file xorg.conf is empty after installation process (under Ubuntu and Xubuntu)!! The command dpkg-reconfigure -phigh xserver-xorg build a simple xorg.conf but did not recognise the driver. So I added to the Device section Driver "siliconmotion".

I had to add fbcon and vga16fb to /etc/modules as well, otherwise the system remains black screened when trying to start with startx from root console. now the system tells me "fatal server error | Addscreen/ScreenInit failed for driver 0"

So far I'm not capable to enter the login screen somehow with 8.10. Before 8.10 there was Ubuntu 6.06 running smoothly ;-(

See the same VT black problem on Hardy with SM720 and also the problem h-gent-o have, after upgrade from Hardy to Intrepid.

I have an old IBM Thinkpad with a Silicon Motion chip that has the same problem. Running Xubuntu 8.04/8.10 the computer boots, X appears to hang (all I get it a blank screen), with no way to access the virtual terminal via the CTRL-ALT-F1 key sequence.

00:02.0 VGA compatible controller [0300]: Silicon Motion, Inc. SM712 LynxEM+ [126f:0712] (rev a0)

# xorg.conf (X.Org X Window System server configuration file)
#
# This file was generated by dexconf, the Debian X Configuration tool, using
# values from the debconf database.
#
# Edit this file with caution, and see the xorg.conf manual page.
# (Type "man xorg.conf" at the shell prompt.)
#
# This file is automatically updated on xserver-xorg package upgrades *only*
# if it has not been modified since the last upgrade of the xserver-xorg
# package.
#
# Note that some configuration settings that could be done previously
# in this file, now are automatically configured by the server and settings
# here are ignored.
#
# If you have edited this file but would like it to be automatically updated
# again, run the following command:
# sudo dpkg-reconfigure -phigh xserver-xorg

Section "Device"
        Identifier "Configured Video Device"
EndSection

Section "Monitor"
        Identifier "Configured Monitor"
EndSection

Section "Screen"
        Identifier "Default Screen"
        Monitor "Configured Monitor"
        Device "Configured Video Device"
EndSection
------------------------------

Xorg.0.log

X.Org X Server 1.5.2
Release Date: 10 October 2008
X Protocol Version 11, Revision 0
Build Operating System: Linux 2.6.24-19-server i686 Ubuntu
Current Operating System: Linux joyride 2.6.27-9-generic #1 SMP Thu Nov 20 21:57:00 UTC 2008 i686
Build Date: 24 October 2008 08:00:16AM
xorg-server 2:1.5.2-2ubuntu3 (<email address hidden>)
        Before reporting problems, check http://wiki.x.org
        to make sure that you have the latest version.
Module Loader present
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.0.log", Time: Mon Dec 8 21:01:43 2008
(==) Using config file: "/etc/X11/xorg.conf"
(==) No Layout section. Using the first Screen section.
(**) |-->Screen "Default Screen" (0)
(**) | |-->Monitor "Configured Monitor"
(**) | |-->Device "Configured Video Device"
(==) Automatically adding devices
(==) Automatically enabling devices
(==) No FontPath specified. Using compiled-in default.
(WW) The directory "/usr/share/fonts/X11/cyrillic" does not exist.
        Entry deleted from font path.
(==) FontPath set to:
        /usr/share/fonts/X11/misc,
        /usr/share/fonts/X11/100dpi/:unscaled,
        /usr/share/fonts/X11/75dpi/:unscaled,
        /usr/share/fonts/X11/Type1,
        /usr/share/fonts/X11/100dpi,
        /usr/share/fonts/X11/75dpi,
        /var/lib/defoma/x-ttcidfont-conf.d/dirs/TrueType
(==) ModulePath set to "/usr/lib/xorg/modules"
(II) Cannot locate a core pointer device.
(II) Cannot locate a core keyboard device.
(II) The server relies on HAL to provide the list of...

Just found a work around for 8.10. The Xorg "vesa" driver in 8.10 is not working either for my SM710 card, but the kernel VESA frame buffer driver works, by appending vga=0x317 to kernel boot arguments. This will give me a 1024x768 virtual console.

Then in Xorg.conf, specify "fbdev" as the driver, and X should work again.

TJ, is this issue still reproducible in a supported release? If so, could you please execute the following command, as it will automatically gather debugging information, in a terminal:
apport-collect 144178

Please ensure you have xdiagnose installed, and that you click the Yes button for attaching additional debugging information.

Unfortunately this driver has suffered bit-rot upstream since the chip-set is ancient and not widely used, and support for it in the 12.04 and 14.04 releases is poor to non-existant.

Marking as "Won't Fix" since we haven't found the expertise to fix it in 7 years.