Bug 18889

Created attachment 20814 [details]
Xorg log with ModeDebug enabled

(verbatim copy of this Launchpad entry: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/304558 )

(verbatim copy from this forum post: http://ubuntuforums.org/showthread.php?t=992882)

I have two new shiny Asus Eee Top ET1602 systems. I tried running Ubuntu 7.10 and 8.10 on them. In the console, and while showing the splash, the screen works fine. When X starts with the intel driver the backlight seems to go off.

I tried multiple way to get it working, but I'm stuck now. The driver exposes the following output ports: VGA, LVDS, Unknown-1, TV (there are no exposed physical connectors on the unit). According to Windows XP, which shipped with the units, the touch panel is connected to the LVDS port, so I disabled the rest of the connectors in xorg.conf explicitly, so they don't interfere with anything.

The vesa driver works fine by the way.

The screen is still black after all my attempts with the intel driver though. Any ideas what I should try to get something displayed?

Thanks

**** Update 1 ****

I'm getting "(EE) intel(0): underrun on pipe B!" errors in the X log periodically.

I also discovered the "--properties" switch for the "xrandr" command, and the related "--output LVDS --set" parameters. When I run "xrandr --properties", it says that the "BACKLIGHT" property is 0, and its range of values is (0,0)... Hmm... I checked the same on my laptop, and there the range is (0, 10781).

There's nothing in /sys/class/backlight on either the Eee Top or my laptop. The "xbacklight" command works on my laptop, and it does nothing on the Eee Top (displays "nan"). Switching the "BACKLIGHT_CONTROL" property to legacy gives me a range of (0,255) on the Eee Top, but changing the brightness value does nothing.

The good news is that the touchscreen works with the "evtouch" driver with little effort (link: http://wiki.linuxmce.org/index.php/Asus_EeeTop).

**** Update 2 ****

I got my hands on a EeePC 1000H, and saw that the brightness controls work on that thing. The eeepc-laptop module controls the backlight. So I tried adding the ATK0110 identified to that module, fingers crossed, hoping that it will work just like that. Well, no luck there. Now I'm really out of ideas, short of reverse engineering the ATK0110 driver that Asus ships for Windows.

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