[mythtv] [mythtv-commits] Ticket #6725: segmentation fault in mythbackend

[Nick Morrott]

On 16/07/2009, Simon Kenyon <simon at koala.ie> wrote:
> MythTV wrote:
>
> > #6725: segmentation fault in mythbackend
> >
> -------------------------------------------+--------------------------------
> >  Reporter:  Simon Kenyon <simon at koala.ie>  |        Owner:  danielk
>    Type:  defect                         |       Status:  infoneeded_new
> >  Priority:  minor                          |    Milestone:  unknown
> Component:  MythTV - DVB/ATSC              |      Version:  head
> Severity:  medium                         |   Resolution:
> Mlocked:  0                              |
> -------------------------------------------+--------------------------------
> > Changes (by stuarta):
> >
> >  * status:  new => infoneeded_new
> >
> >
> >
> >
>  what more information do you need?
>  i'm a little confused
>  not sure if you need additional information from me
>
>  the backend has a PVR-350 connected to a STB using RGB
>  it has two DVB-S cards, a Nexus-S and and a budget 1500
>  it is hard to tell remotely, but i think i am using the 1500
>  i only have one DVB card configured in at the moment

Your second log contains:

2009-07-14 09:40:03.310 MythSocket(909c40:36): readStringList: Error, timeout.
2009-07-14 09:40:03.314 Slave backend: newyork no longer connected
2009-07-14 09:40:03.315 PlaybackSock::SendReceiveStringList(): No response.
2009-07-14 09:40:03.315 Reschedule requested for id 0.
2009-07-14 09:40:03.315 PlaybackSock, Error: IsBusy:
QUERY_REMOTEENCODER 61 gave us no response.

Do you mean to have a slave backend on the network? If you do, is it cardless?

Echoing Mike Dean's frequent suggestion, I would do a "Delete all
capture cards" and then just configure the card you are using for
testing. Your log indicated you are using the DVB-S card that uses the
"ST STV0299 DVB-S" frontend (DVB adapter 1).

I've not had any mythbackend stability issues on trunk @ 20830. The
channel scanner is borken, but once up and running the backend seems
fairly stable (IME).

The other thing I noticed looking through your second log is that your
backend is trying to tune to serviceid 1111 on the 11344000H mux:

2009-07-14 09:35:17.270 DVBChan(46:/dev/dvb/adapter1/frontend0):
Opening DVB channel
2009-07-14 09:35:17.270 DVBChan(46:/dev/dvb/adapter1/frontend0):
SetChannelByString(1111):
2009-07-14 09:35:17.279 DVBChan(46:/dev/dvb/adapter1/frontend0):
11344500 qpsk a auto auto a a auto a h
2009-07-14 09:35:17.280 DVBChan(46:/dev/dvb/adapter1/frontend0): Old
Params: 11623080 qpsk a auto auto a a auto a h
			DVBChan(46:/dev/dvb/adapter1/frontend0): New Params: 11344500 qpsk
a auto auto a a auto a h
2009-07-14 09:35:17.280 DVBChan(46:/dev/dvb/adapter1/frontend0):
Tune(): Tuning to 1594500kHz
2009-07-14 09:35:17.281 dvbchannel.cpp:wait_for_backend: Status:
2009-07-14 09:35:17.281 DVBChan(46:/dev/dvb/adapter1/frontend0):
Tune(): Frequency tuning successful.
2009-07-14 09:35:17.282 DVBChan(46:/dev/dvb/adapter1/frontend0):
SetChannelByString(1111): Tuned to frequency.
2009-07-14 09:35:17.282 TVRec(46): Starting Signal Monitor
2009-07-14 09:35:17.283 TVRec(46): SetupSignalMonitor(1, 0)
2009-07-14 09:35:17.283 DVBChan(46:/dev/dvb/adapter1/frontend0):
Opening DVB channel
2009-07-14 09:35:17.284 DVBSM(/dev/dvb/adapter1/frontend0): Can
measure Signal Strength
2009-07-14 09:35:17.285 DVBSM(/dev/dvb/adapter1/frontend0): Can measure S/N
2009-07-14 09:35:17.286 DVBSM(/dev/dvb/adapter1/frontend0): Can
measure Bit Error Rate
2009-07-14 09:35:17.286 DVBSM(/dev/dvb/adapter1/frontend0), Warning:
Can not count Uncorrected Blocks
			eno: Function not implemented (38)
2009-07-14 09:35:17.287 SM(/dev/dvb/adapter1/frontend0)::RemoveFlags:
Seen() Match() Wait(UB,)
2009-07-14 09:35:17.287 DVBSM(/dev/dvb/adapter1/frontend0):
DVBSignalMonitor::ctor initial flags Seen() Match() Wait(Sig,SNR,BER,)
2009-07-14 09:35:17.590 TVRec(46): Signal monitor successfully created
2009-07-14 09:35:17.590 TVRec(46): Setting up table monitoring.
2009-07-14 09:35:17.593 Using profile 'Live TV' to record
2009-07-14 09:35:17.593 TVRec(46): DVB service_id 1111 on net_id 2 tsid 2313
2009-07-14 09:35:17.594
DTVSM(/dev/dvb/adapter1/frontend0)::SetDVBService(transport_id: 2313,
network_id: 2, service_id: 1111):


No such serviceid exists on that mux - so I'm not sure if the backend
is getting stuck somewhere, or if it gracefully recovers and segfaults
somewhere else later independent of this. You might try creating a new
temporary video source and then import a current channels.conf created
by dvbscan (or equivalent on Gentoo) so that your channels are all
good.

Cheers,
Nick

-- 
Nick Morrott

MythTV Official wiki:
http://mythtv.org/wiki/
MythTV users list archive:
http://www.gossamer-threads.com/lists/mythtv/users

"An investment in knowledge always pays the best interest." - Benjamin Franklin