Richard Jones' Log: HTPC update

Sun, 12 Jun 2005

My Home Theatre PC project is progressing slowly. Very slowly.

The only stumbling block is the VIA chipset on the motherboard that handles video and TV-Out. It's a K8M800 chipset, and is supported by the open-source unichrome project (quite different from VIA's "open source initiative", which is anything but open-source). Thanks to that project, I have the chipset displaying X11 on a monitor fine. There's even some acceleration beyond the standard VESA drivers. Unfortunately, it seems the K8M800 chipset has a bug. Or the BIOS does. Or the Linux kernel does (though I'm given the impression that the chipset is at fault). Regardless who is at fault, there's a runaway IRQ 16 that the kernel can't cope with, and causes the DRI module to switch off (before anyone says anything, no, APIC isn't a cause or solution). In the end, I have to disable Vblank IRQs, which degrades performance. I can still play DVD full-screen, it's just at a higher CPU load.

On the TV-Out front, things aren't working there either. I've got a picture, but ... well it's not so good (it looks to me as though the interlacing isn't synchronising correctly).

So I'm still thinking that I will need to get a separate video card for the box. Or I've been thinking about throwing in the towel and just using the little box as my new desktop. That'd be a shame, and I'm willing to give the Unichrome developers more time to try to sort out the TV-Out issues.