XO: USB video adapter (sisusb)

[Terry Stewart]

Hello everyone,

I am attempting to test the sisusb support under Snap3 on the XO
laptop.  This should allow the use of a USB VGA adapter so that an
external monitor/projector can be used on the XO.  I have successfully
done this with Ubuntu on the XO, and it seems to work fine under Sugar
(the system that comes with the XO) as well (see
<http://wiki.laptop.org/go/Remote_Display> for details).  However, I
have been unable to do this under Fedora.

My approach has been to boot up the machine with Snap3, modify
xorg.conf, plug in the usb vga adapter (GXT USB 2.0 To VGA Adapter
(UVA200) <http://www.futureshop.ca/catalog/proddetail.asp?logon=&langid=EN&sku_id=0665000FS10091172&catid=25607>)
and then reset X (ctrl-alt-backspace).  When I do this I get a blank
screen on both displays (the LCD and the VGA adapter) with a repeating
flicker every few seconds as if they are changing display modes.  The
LCD seems to be alternating between a text mode and a graphics mode,
since there is a visible blinking cursor half the time (exactly like a
blank vt).

My best guess is there is some sort of initialization failure
happening, and it keeps retrying.  If I unplug the USB VGA adapter
while this is occurring, it stops flickering and successfully starts X
(but without the second screen, of course).

Here is what I added to xorg.conf:
------------------
Section "Device"
	Identifier "Device1"
	VendorName "SiS"
	BoardName "SiS"
	Driver "sisusb"
EndSection

Section "Monitor"
	Identifier "Monitor1"
	VertRefresh 50-75
	HorizSync 30-90
	Option "DPMS"
EndSection

Section "Screen"
	Identifier "Screen1"
	Device "Device1"
	Monitor "Monitor1"
	DefaultDepth 16
	SubSection "Display"
		Depth 16
		Modes "1024x768"
	EndSubSection
EndSection
----------------

I also added this to the ServerLayout:
--------------
	Screen      1  "Screen1" 0 0
--------------


The last bit of Xorg.0.log looks like this:
--------------
(II) Loading /usr/lib/xorg/modules//libshadow.so
(II) Module shadow: vendor="X.Org Foundation"
	compiled for 1.5.2, module version = 1.1.0
	ABI class: X.Org ANSI C Emulation, version 0.4
(--) RandR disabled
(II) SISUSB(1): Setting standard mode 0x4a
(II) SISUSB(1): Framebuffer from (0,0) to (1023,7902)
(==) SISUSB(1): Backing store disabled
(**) Option "dpms"
(**) SISUSB(1): DPMS enabled
(II) SISUSB(1): Initialized SISCTRL extension version 0.1
(II) SISUSB(1): Registered screen 1 with SISCTRL extension version 0.1
(--) RandR disabled

Backtrace:
0: /usr/bin/Xorg(xorg_backtrace+0x3b) [0x812b8db]
1: /usr/bin/Xorg(xf86SigHandler+0x51) [0x80bc911]
2: [0x130400]
3: /usr/bin/Xorg(xf86EnterServerState+0x54d) [0x80b14ad]
4: /usr/bin/Xorg(xf86PostScreenInit+0x213) [0x80b2b53]
5: /usr/bin/Xorg(InitOutput+0x335) [0x80a3d65]
6: /usr/bin/Xorg(main+0x279) [0x806b4e9]
7: /lib/libc.so.6(__libc_start_main+0xe5) [0x42e6d5]
8: /usr/bin/Xorg [0x806aad1]

Fatal server error:
Caught signal 11.  Server aborting

(II) Screen 0 shares mem & io resources
(II) Screen 1 shares mem & io resources
-----------------------

Does anyone have any suggestions as to what else I can try for this?

Thank you,
Terry