[mythtv-users] Firewire on a combo backend/frontend

John P Poet jppoet at gmail.com
Wed Aug 2 01:22:05 UTC 2006


On 7/31/06, Allan Wilson <allanwilson at gmail.com> wrote:
> On 7/31/06, Allan Wilson <allanwilson at gmail.com> wrote:
> >
> > On 7/31/06, John P Poet <jppoet at gmail.com > wrote:
> >
> > > On 7/31/06, John P Poet <jppoet at gmail.com> wrote:
> > > <snip>
> > > > Unfortunately, I now had an audio problem.  The sound would drop-out
> > > > for a fraction of a second, every couple of seconds.  This only
> > > > happened if I was recording via firewire at the same time.  I figured
> > > > my firewire port and my sound card must be sharing an interrupt, but a
> > > > quick look at the motherboard manual disproved that theory.  I then
> > > > check the latencies of those two devices (lspci) and discovered that
> > > > both were at 32.  After adjusting both up to 64 (setpci), my audio
> > > > problem is also solved.
> > >
> > > Hmmm.  Unfortunately, adjusting the latency has not solved the problem
> > > after all.  It has reduced it, but it is still there.
> > >
> > > I guess I will try a different PCI slot for the sound card next.
> > >
> > > John
> > > _______________________________________________
> > > mythtv-users mailing list
> > > mythtv-users at mythtv.org
> > > http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
> > >
> >
> >
> > Attached is my sa3250ch.c file. You will probably have to update lines 32
> and 33 to match your box and this one has Steve's patch built in it. If it
> helps you out post back to the list and I will just post the code. Don't
> want to send an attachment to the whole list.
> >
> >
> > Allan
> >
> >
>
> I took a look at my look at my latency settings and my audio card was set to
> 0. I read on the wiki how to change that but I'm not having any luck. I
> used:
>
>  sudo setpci -v -s 00:1f.5 latency_timer=40
>
> and lspci -v still showed me
>
> 0000:00:1f.5 Multimedia audio controller: Intel Corp. 82801EB/ER
> (ICH5/ICH5R) AC
> '97 Audio Controller (rev 02)
>         Subsystem: Asustek Computer, Inc. P4P800 Mainboard
>         Flags: bus master, medium devsel, latency 0, IRQ 17
>         I/O ports at e800 [size=256]
>         I/O ports at ee80 [size=64]
>         Memory at f7fff800 (32-bit, non-prefetchable) [size=512]
>
> Am I running the command wrong. I thought I would try this before the patch.
> Thanks for the idea on this I had not run across it before and it explains
> why my audio has been so bad when other things are going on.
>
> Allan

There is probably an easier way, but...

I ran lspci to get a listing of cards:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
lspci
05:08.0 Multimedia audio controller: VIA Technologies Inc. ICE1712
[Envy24] PCI Multi-Channel I/O Controller (rev 02)
05:0b.0 FireWire (IEEE 1394): Texas Instruments TSB43AB22/A
IEEE-1394a-2000 Controller (PHY/Link)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


Made a note of their ids, then ran "lspci -n" to get the vendor and
device codes"
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
lspci -n
05:08.0 0401: 1412:1712 (rev 02)
05:0b.0 0c00: 104c:8023
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


Then I used setpci to adjust the latency:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
setpci -v -d '104c:8023' latency_timer=40
setpci -v -d '1412:1712' latency_timer=40
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Hope that helps.

John


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