[mythtv-users] Problems with the VIA KM400 chipset

[Tim Tait]

Jarod Wilson wrote:

> On Jun 4, 2004, at 20:11, BP wrote:
>
>> Andy Long wrote:
>>
>>> Does anyone know if there are problems using the PVR-250 on a board  
>>> with the
>>> VIA KM400 chipset?  I'm looking at getting the Abit VA-10
>>> (http://www.newegg.com/app/viewProductDesc.asp?description=13-127 
>>> -159&catalo
>>> g=23&manufactory=BROWSE), but have heard that there are problems 
>>> with  the
>>> ivtv driver and via chipsets.  Is that just limited the the  
>>> KT133/KT266, or
>>> is it all Via chips?
>>> Thanks.
>>
>>
>> I've not had a single problem since I switched to my Abit VA-10 
>> about  six months ago.  It's been running 24x7 with an occasional 
>> reboot for  kernel updates.  I'm using the ivtv 0.1.9 driver patched 
>> for 2.6 and  the 2.6.4 kernel.  My previous board (Chaintech 7NIF2 
>> (NForce2)) was  nothing but trouble and acted like the reported VIA 
>> 266 ivtv bug.
>
>
> My MSI KM4M-L (KM400-based micro ATX) board has no problems at all. 
> But  then neither does my KM266 board, and my Chaintech 7NIF2 has 
> been  flawless (its been my master backend with two cards in it, 
> rock-solid  for at least 8mo)...

There were issues on many AMD mobo's with the Athlon "CPU Disconnect" 
feature, particularly nForce2's. It has something to do with extra delay 
and a race condidition if "CPU disconnect" is enabled. It caused my FIC 
AU13 (who's BIOS does not loet you turn  that feature off) to lock up 
during long builds. Turning off HD DMA reduced the frequency but did not 
eliminate it. Even hitting "Caps lock" on/off during the build could 
trigger it. The fix was simple - turn off "CPU Disconnect" in the BIOS 
if possible, or via "athcool" if not. The downside was a slightly hotter 
cpu. Turning of the APIC also works, if you habe enough interrupts 
available. There were some kernel hacks to fix it through long delays 
before reading interrupts (ick). Whatever the cause/fix, I don't seem to 
have a problem anymore with the 2.4.26 kernel, though it may be too soon 
to be sure.

Some or all of this may apply to Via chipsets. I also have an MSI KM2M 
Combo-L running a samba server for a year w/o problems - but it 
defaulted to "CPU Disconnect" off in the BIOS, and when I turn it on 
things go to hell - though mostly it results in really lousy PCI IDE 
controller performance, not lockups. I have not tried having it on for 
2.4.26 kernel.

Tim