[mythtv-users] Fw: [ivtv-users] PVR-150 fails after working for a few hours/days at a time, zero-byte recordings

[John Drescher]

On Fri, Aug 28, 2009 at 10:29 AM, Quinten
Steenhuis<q.steenhuis at yahoo.com> wrote:
>
> This is a message I sent to the IVTV list, after searching the archives for a potential solution. My thought was to send it to the more specialized list, but if anyone has other ideas on this list, I'd be willing to try before spending more $$.
>
> Quick answer to Greg's questions:
>
>
> Gigabyte GA-M78SM-S2H (from my memory-may be slightly different model), with Athlon 64 X2.
> DDR ram, two modules
> Mythbuntu 8.10
> Kernel 2.6.27-14 SMP (stock mythbuntu, but I did download and install custom ALSA modules)
>
> It generally works for a short while, sometimes for a few days, before the error pops up. When the error occurs, I can't record via MythTV or via cat /dev/video0 | mplayer -
>
> My other tuner, an HD Homerun, works.
>
>
> ----- Forwarded Message ----
>>
>> Hi,
>>
>> I have a pvr-150 low profile card, which I use for watching analog cable tv.
>>
>> Usually it works briefly after a reboot, but inevitably I get the dreaded DMA
>> errors, which look like this:
>>
>> [104235.184516] ivtv0: DMA TIMEOUT 00000001 0
>>

This used to happen for some users several years ago (even before the
driver made it into the mainline kernel). I had this on my master
backend back in 2007 or so.. However I have not had not seen that
since and I also have not  seen much of this on the last 2 years or
so. Two things I remember from back then to try were disabling
frequency scaling and/or disabling SMP.

Also (i just remembered) you can completely get around the DMA problem
by forcing the ivtv driver to use PIO instead. This is what I did on
the ivtv 0.10.X out of kernel driver. I am not sure if this workaround
still works on the in source kernel.

Here is the patch for 0.10.X

http://github.com/drescherjm/jmdgentoooverlay/blob/46cad12ba2d03a9c1a85f64663382d31e21a429e/media-tv/ivtv/files/ivtv-0.10.3-pio.patch

John