[Openchrome-users] Poor Performance / DDC probe issues

[Alexander Griesser]

Hey there,

I purchased a few HP Thinclients (t5545) and am now facing problems with 
those pesky graphics chips in there.

This is what I'm talking about:

00:01.0  1106:1122   VGA compatible controller: VIA Technologies, Inc. 
VX800/VX820 Chrome 9 HC3 Integrated Graphics (rev 11)

Out of the box, everything seems to run quite well, but after deploying
some of these to my customers, I noticed a few problems. I was able to
fix most of them on my own, but two major things are still open and
that's why I'm asking for help in here.

First problem: ddcprobe doesn't work with every display as it seems and
with some displays, it only works on the VGA port.

Here's the ddcprobe output on the t5545 connected via DVI to an AOC display:

[lxtc-11953 - ~ #] ddcprobe
vbe: VESA 3.0 detected.
oem: VIA VX800
vendor:
product:
memory: 32768kb
mode: 640x480x256
mode: 640x480x64k
mode: 640x480x16m
mode: 800x600x256
mode: 800x600x64k
mode: 800x600x16m
mode: 1024x768x256
mode: 1024x768x64k
mode: 1024x768x16m
mode: 1280x1024x256
mode: 1280x1024x64k
mode: 1280x1024x16m
mode: 1600x1200x256
mode: 1600x1200x64k
edid:
edidfail


When I unplug the DVI cable and plug in the VGA cable, the output looks 
like this:

[lxtc-11953 - ~ #] ddcprobe
vbe: VESA 3.0 detected.
oem: VIA VX800
vendor:
product:
memory: 32768kb
mode: 640x480x256
mode: 640x480x64k
mode: 640x480x16m
mode: 800x600x256
mode: 800x600x64k
mode: 800x600x16m
mode: 1024x768x256
mode: 1024x768x64k
mode: 1024x768x16m
mode: 1280x1024x256
mode: 1280x1024x64k
mode: 1280x1024x16m
mode: 1600x1200x256
mode: 1600x1200x64k
edid:
edid: 1 3
id: a784
eisa: AOCa784
serial: 0000b820
manufacture: 4 2006
input: sync on green, analog signal.
screensize: 34 27
gamma: 2.200000
dpms: RGB, active off, no suspend, no standby
timing: 720x400 at 70 Hz (VGA 640x400, IBM)
timing: 720x400 at 88 Hz (XGA2)
timing: 640x480 at 60 Hz (VGA)
timing: 640x480 at 67 Hz (Mac II, Apple)
timing: 640x480 at 72 Hz (VESA)
timing: 640x480 at 75 Hz (VESA)
timing: 800x600 at 60 Hz (VESA)
timing: 800x600 at 72 Hz (VESA)
timing: 800x600 at 75 Hz (VESA)
timing: 832x624 at 75 Hz (Mac II)
timing: 1024x768 at 87 Hz Interlaced (8514A)
timing: 1024x768 at 70 Hz (VESA)
timing: 1024x768 at 75 Hz (VESA)
timing: 1280x1024 at 75 (VESA)
ctiming: 1280x1024 at 60
dtiming: 1280x1024 at 88
monitorserial: 17561HA04713
monitorrange: 30-83, 55-75
monitorname: AOC LM729


Since I'm parsing the ddcprobe output during the boot process to gather 
information about the best possible resolution, this process fails when
connected via DVI.

Any idea how I can work around this?

Second problem:
My thinclients connect to terminal servers (doesn't make a difference in
performance if I connect via RDP or Citrix ICA) and when I open a simple
webbrowser in the terminal session and I scroll up and down quickly,
CPU usage in Xorg goes up to >90% and the scrolling looks extremely laggish.

I'm using the latest openchrome driver from openchrome.org so far (first 
I tried the one in the debian repo, no difference) and I also
applied the no_dri.patch (no difference) and then I tried to "use swrast 
for the VX800 cards"-patch (no difference).

I also tried the proprietary driver from VIA (Unified GFX driver Ver 
87a-55689 for Ubuntu 10.04(04Aug10) (2.1M)) but this one wasn't better
performancewise, at least not much, scrolling was still very slow.

Any ideas how I can speed up the scrolling or the overall 2D speed?
I don't need 3D acceleration or anything like that, all I need is
a reliable 2D implementation which works pretty well wrt/ performance.

Is anyone able to help here?
Are there any hidden configuration options in the openchrome driver
which can be used to finetune things like that?

Do you need any logs or configuration files from me or is this a known
problem?

Thanks in Advance,
Alex