X Video finally works - Poulsbo and Linux on the MSI Wind U110 - Fix for BUG: kernel NULL pointer dereference at 00000000

If you tried to get poulsbo to run on your system and you get a message like this, you should try the fix posted below.

"kernel BUG: unable to handle kernel NULL pointer dereference at 00000000" (2.6.28)

"kernel BUG: unable to handle kernel NULL pointer dereference at (null)" (2.6.31)

Thanks to a post on Ubuntu's bugzilla, the poulsbo video module now finally works on my MSI Wind U110 (full review & installation guide). Download the psb-kernel-source module You only have to comment out the two lines in intel_lvds.c starting with

if (edid)
....

e.g.
/* if (edid)
drm_add_edid_modes(output, edid); */

Then reconfigure the package and it should be recompiled. The next time you start it, it should work instead of creating kernel BUG

Update:

Xvideo actually works better than in Directx video in Windows XP, where I often see blocky video scaling. The CPU usage is not too high, either. Currently it's only working under Ubuntu 9.04 for me. Though I had managed to compile the module with kernel 2.6.30 before, I don't remember how I did that... And I haven't gotten actual video acceleration to work yet.

Of course I'll keep you updated and I'll post a little howto once it's all working. But feel free to ask, anyway. And thanks so much to the person from the Ubuntu bugzilla who helped me to finally get it all working!!!

Update2: Keep checking the page. I will post a link to an archive with a script that will manage the compilation in Ubuntu 9.10. If someone could help me figure out how to, I'd love to create, upload and post a .deb for dkms so it all works automatically... Or ultimately, we could modify the driver to check for the MSI's signature and then skip the edid check.

I've created a package for Karmic that you can use to manually install the driver with the fix already applied: http://www.megaupload.com/?d=BB23R7K2. Extract it and execute the script make_psb.sh, then reboot and try to modprobe psb. Let me know when the 10 downloads run out and it it works for you.

Update3: Here is a step by step howto. It explains setting up X and then VAAPI (hardware video decoding) in Kubuntu 9.10.

My script for making the psb module out of the package:

KERNEL=/lib/modules/`uname -r`/

make KERNELRELEASE="$(uname -r)" LINUXDIR="/lib/modules/$(uname -r)/build" DRM_MODULES=psb || exit 1;

sudo cp drm.ko $KERNEL/kernel/drivers/gpu/drm/drm.ko

sudo mkdir -p $KERNEL/updates/dkms

sudo cp psb.ko $KERNEL/updates/dkms/psb.ko

ls -l $KERNEL/kernel/drivers/gpu/drm/drm.ko $KERNEL/updates/dkms/psb.ko

sudo depmod -a