[mythtv-users] Problem with a second DVB card, help needed

[David Petticrew]

Otto Kolsi wrote:
>>> With all the other apps (dvbscan, dvbstream, kaffeine, mplayer) I can
>>> successfully tune to channels, and watch programs with both cards. With
>>> mplayer I can succesfully watch two different programs from separate
>>> cards at the same time.
>>>
>>> Problem is that when I try to use these two cards *at the same time*
>>> with Myth, the second card is not working. First card records program
>>> fine but although Myth starts to record a program, the recording is
>>> never made with the second card (the file does not exist).
>>>
>>> And more strangely, after this kind of failure, if I stop the backend
>>> I'm not anymore able to use any other apps with the failed card. Tuning
>>> doesn't work etc. After reboot everything is okay again. How is this
>>> possible? Could apps using DVB API misuse the card somehow so that it is
>>> leaved to non-working state? Or does this clearly show that this is
>>> kernel / driver issue?
>> What are your logfiles (mythbackend particularly) showing?  Is there an
>> error message when the second card tries to start a recording? What size is
>> your ringbuffer setting? What does /proc/meminfo show for free/used vmalloc
>> space? I have just been through something similar (perhaps - I didn't notice
>> that particular backend lockup) with 3 DVB cards, the 3rd one wouldn't work
>> at the same time as the other two. All three are able to record
>> simultaneously now though, with a larger vmalloc kernel parameter.
>> http://www.gossamer-threads.com/lists/mythtv/users/223469
>>
>> Henry
> 
> Now I managed to reproduce the problem outside Myth. If I run mplayer 
> for both cards at the same time and then also run "updatedb", the second 
> mplayer either freezes or dies. Somehow the HD activity interferes with 
> the card.
> 
> So this is not a Myth issue. I've checked that cards are not sharing 
> interrupts with other devices. Any other hints, what to check or change? 
> Cards have PCI latency 64, I think I'll try to play with those to see if 
> anything changes.

I've had a similar issue and this time it definitely is a mythtv issue, 
since it only occurs since I upgraded to 0.20. I have two cards, a DVB 
card (avermedia 771) and a PVR 150. When the PVR card kicks in it stops 
the DVB card from recording, although mythtv still says it is recording. 
If I start the PVR recoding first then the PVR card will start but it 
stops after around 3 minutes. Recording from two channels worked fine 
with mythtv 0.19 but doesn't seem to work for 0.20. Here's one of the 
relevant sections of the log file.

0: start_time: 0.036 duration: 232.448
1: start_time: 0.025 duration: 232.407
stream: start_time: 0.276 duration: 2582.884 bitrate=4239 kb/s
2006-10-22 21:50:00.854 AFD: Opened codec 0x836b840, id(MPEG2VIDEO) 
type(Video)
2006-10-22 21:50:00.884 AFD: Opened codec 0x836bb80, id(MP2) type(Audio)
2006-10-22 21:50:02.254 TVRec(2): Changing from None to RecordingOnly
2006-10-22 21:50:02.260 TVRec(2): HW Tuner: 2->2
2006-10-22 21:50:02.274 Started recording: Torchwood "2/13-Day One": 
channel 2502 on cardid 2, sourceid 2
2006-10-22 21:50:03.285 Reschedule requested for id 0.
2006-10-22 21:50:03.546 Scheduled 22 items in 0.3 = 0.00 match + 0.26 place
2006-10-22 21:51:01.125 MainServer::HandleAnnounce Playback
2006-10-22 21:51:01.126 adding: localhost as a client (events: 0)
2006-10-22 22:00:03.059 TVRec(1): Changing from None to RecordingOnly
2006-10-22 22:00:03.096 TVRec(1): HW Tuner: 1->1
2006-10-22 22:00:04.128 ret_pid(25823) child(25823) status(0x0)
2006-10-22 22:00:04.128 External Tuning program exited with no error
2006-10-22 22:00:04.347 Started recording: Mythbusters "Crimes and 
Mythdemeanours Part 1": channel 1008 on cardid 1, sourceid 1
2006-10-22 22:00:26.495 MainServer::HandleAnnounce Playback
2006-10-22 22:00:26.496 adding: localhost as a client (events: 0)
2006-10-22 22:01:34.928 MainServer::HandleAnnounce Monitor