[mythtv-users] DMA Read errors and inter chipset (Abit BP6 Motherboard)

Maarten mythtv at ultratux.org
Mon Aug 16 18:07:26 EDT 2004


On Monday 16 August 2004 21:13, MythTV wrote:
> Greeting,
>
> I am trying to figure out of other people have this MOBO and are seeing 
> DMA errors with IVTV and their PVR 350

I have this mobo but don't use it for Mythtv (I'd reckon its underpowered).
Still, I'll try to contribute what I can...

> I picked up a dual 466  Mobo for cheap as I was having problems with my
> MythTV/350 TVOut machine (frontend backend are on same PC, files stored to
> NFS Server on another machine)
>
> needless to say I am still having MythTV failing to recoard shows.  WHen
> this happens even deleting any shows does not work.  the backend must be
> restarted.  To even record, the ,machine must be powered off (warm reboot
> does not seem to fix it)  Anyways  when searching the logfiles I saw.
>
> Aug 14 18:53:21 mythtv kernel: ivtv: DMAP not set
> Aug 14 19:22:53 mythtv kernel: ivtv: DMAP not set
> Aug 14 20:01:43 mythtv kernel: ivtv: DMA read error. Result=0x00000002
> Aug 14 20:05:23 mythtv kernel: ivtv: DMA read error. Result=0x00000002
> Aug 14 20:15:32 mythtv kernel: ivtv: DMA read error. Result=0x00000002
> Aug 14 20:15:51 mythtv kernel: ivtv: DMA read error. Result=0x00000002
> Aug 14 20:16:46 mythtv kernel: ivtv: DMA read error. Result=0x00000002
> Aug 14 20:18:25 mythtv kernel: ivtv: DMA read error. Result=0x00000002
> Aug 14 20:21:14 mythtv kernel: ivtv: DMA read error. Result=0x00000002
> Aug 14 20:24:43 mythtv kernel: ivtv: DMAP not set
> Aug 14 20:27:12 mythtv kernel: ivtv: DMAP not set
> Aug 14 23:52:21 mythtv kernel: ivtv: giving up waiting for DMA pending
> clear
>
> When I searched for the above all I found was reference to VIA chipsets
> having this issue with IVTV.  I am running  the following board.

The Abit BP6 does not have a VIA chipset but the (very good and ultra-stable) 
intel BX chipset.  One of the best chipsets ever made, even if very old by 
now.  But definitely Rock Solid.

> ALl the cards where the same as in my last config in which I used a PII 333
> (intel) excep for the HighPoint controller (onboard) which is only on this
> MOBO (Abit BP6 dual Celeron)

Please heed this advice (my own experience) DO NOT USE that highpoint 
controller !   EVER.   It has severe problems, will probably crash when 
setting DMA and / or will not even permit (error-free) DMA transfers.
Again: do not use.  Connect your drives to the BX onboard controller, or -if 
you really must have ATA 66 or better- buy a promise TX2 card.

>
> Am I screwed with this MOBO and MythTV?

Well, yes and no.  My Pentium3/500 laptop manages just to replay my 480x480 
recordings.  So to have a dual celeron 400 (or so) system as backend is 
really stretching it a bit.  Even IF mythtv fully supports SMP and takes full 
advantage or the two processors, it still isn't much to go on.  Remember 
those celerons lacked many if not all of the later optimisations like MMX et 
al.  Those celerons were like the Pentium 2 series but crippled, so they 
really compare badly to the newer Pentium 3.
   
But, _then_again_ you are using a PVR350 so CPU power isn't needed so you may 
as well forget the whole story above.  
So: If I were you, I'd disconnect the drives from the HPT366 controller (blue 
connectors) if they are there now, and retry with the onboard (black) 
connectors.  And make sure DMA is enabled !

Another thing:  The BIOS on these boards is critical.  Make sure you have 
(this is from memory though!) the qq version BIOS.  Refer to google on that.
Read up on it thorougly though; newer and older BIOSes exist but the qq BIOS 
was the best (IIRC).  Experiment as well with the BIOS (APIC etc.) settings. 

Good luck
Maarten

-- 
Linux: Because rebooting is for adding hardware.



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