[mythtv] backend crash on dvb channel change, backtrace included

Tuomas Jormola tjormola at cc.hut.fi
Tue May 4 07:08:04 EDT 2004


On 3.5.2004, at 12:46, Brian May wrote:
>
> I get the impression I may be dealing with multiple problems here, it
> doesn't make it easy to debug. Some problems are specific to the
Yes, I reported about weird DVB problems on the mythtv-users list but 
received no replies. mythbackend doesn't segfault here as in Juha's 
case but problems exist when changing channels nevertheless.

Begin forwarded message:

> From: Tuomas Jormola <tjormola at cc.hut.fi>
> Date: 26. huhtikuuta 2004 21:22:27 GMT+03:00
> To: mythtv-users at mythtv.org
> Subject: [mythtv-users] DVB-C and hangs when changing channels
> Reply-To: tjormola at cc.hut.fi, Discussion about mythtv 
> <mythtv-users at mythtv.org>
>
> Hello,
>
> I live in a dorm with small cable network covering the campus area. 
> I'm using
> MythTV from current CVS and Technotrend DVB-C 2.1 card with stock 
> kernel 2.6.5
> drivers. I don't know if it's the network or my system but sometimes 
> changing
> channels fails. The backend just hangs with these log entries (running
> mythbackend -v all).
>
> 2004-04-26 20:40:26 DVB#0 Trying to tune to channel 14.
> 2004-04-26 20:40:26 DVB#0 Frequency: 290000000 Symbol Rate: 7146000. 
> Inv:Auto Fec:None Mod:64
> 2004-04-26 20:40:27 DVB#0 Waiting for frontend event after tune.
> 2004-04-26 20:40:27 DVB#0 WARNING - Status: NO LOCK!
> 2004-04-26 20:40:27 DVB#0 Status: CARRIER | VITERBI | SIGNAL | SYNC | 
> LOCK.
> 2004-04-26 20:40:27 DVB#0 Successfully tuned to channel 14.
> 2004-04-26 20:40:27 2       ok
> 2004-04-26 20:40:27 DVB#0 Adding pid 644, type 0
> 2004-04-26 20:40:27 DVB#0 Adding pid 513, type 1
> 2004-04-26 20:40:27 16      1[]:[]1021313024
> 2004-04-26 20:40:27 121     World Business Report[]:[] []:[] []:[] 
> []:[]200...
> 2004-04-26 20:40:27 7       0[]:[]0
> 2004-04-26 20:40:27 DVB#0 Adding pid 1001, type 2
> 2004-04-26 20:40:28 DVB#0 WARNING - Uncorrectable error in packet, 
> dropped.
> 2004-04-26 20:40:28 DVB#0 WARNING - Uncorrectable error in packet, 
> dropped.
> 2004-04-26 20:40:29 DVB#0 WARNING - No data from card in 1 second.
> 2004-04-26 20:40:29 DVB#0 WARNING - Uncorrectable error in packet, 
> dropped.
> 2004-04-26 20:40:29 DVB#0 WARNING - Uncorrectable error in packet, 
> dropped.
> 2004-04-26 20:40:30 DVB#0 WARNING - No data from card in 1 second.
> 2004-04-26 20:40:31 DVB#0 WARNING - Uncorrectable error in packet, 
> dropped.
> 2004-04-26 20:40:31 DVB#0 WARNING - Uncorrectable error in packet, 
> dropped.
> 2004-04-26 20:40:32 DVB#0 WARNING - Uncorrectable error in packet, 
> dropped.
> 2004-04-26 20:40:32 DVB#0 WARNING - Uncorrectable error in packet, 
> dropped.
> 2004-04-26 20:40:32 DVB#0 WARNING - Uncorrectable error in packet, 
> dropped.
> 2004-04-26 20:40:33 DVB#0 WARNING - Uncorrectable error in packet, 
> dropped.
> 2004-04-26 20:40:34 DVB#0 WARNING - Uncorrectable error in packet, 
> dropped.
> 2004-04-26 20:40:34 DVB#0 WARNING - Uncorrectable error in packet, 
> dropped.
> 2004-04-26 20:40:34 DVB#0 WARNING - Uncorrectable error in packet, 
> dropped.
> 2004-04-26 20:40:35 DVB#0 WARNING - No data from card in 1 second.
> 2004-04-26 20:40:36 DVB#0 WARNING - Uncorrectable error in packet, 
> dropped.
> 2004-04-26 20:40:36 DVB#0 WARNING - Uncorrectable error in packet, 
> dropped.
> 2004-04-26 20:40:36 DVB#0 WARNING - Uncorrectable error in packet, 
> dropped.
> 2004-04-26 20:40:37 DVB#0 WARNING - Uncorrectable error in packet, 
> dropped.
> 2004-04-26 20:40:37 DVB#0 WARNING - Uncorrectable error in packet, 
> dropped.
> 2004-04-26 20:40:38 DVB#0 WARNING - Uncorrectable error in packet, 
> dropped.
> 2004-04-26 20:40:38 DVB#0 WARNING - Uncorrectable error in packet, 
> dropped.
> 2004-04-26 20:40:39 DVB#0 WARNING - No data from card in 1 second.
> 2004-04-26 20:40:40 DVB#0 WARNING - Uncorrectable error in packet, 
> dropped.
> 2004-04-26 20:40:41 DVB#0 WARNING - No data from card in 1 second.
> 2004-04-26 20:40:41 DVB#0 WARNING - Uncorrectable error in packet, 
> dropped.
> 2004-04-26 20:40:41 DVB#0 WARNING - Uncorrectable error in packet, 
> dropped.
> 2004-04-26 20:40:42 Couldn't read data from the capture card in 15 
> seconds.  Game over, man.
> 2004-04-26 20:40:42 1       0
> 2004-04-26 20:40:42 1       0
> 2004-04-26 20:40:42 1       0
> 2004-04-26 20:40:42 DVB#0 WARNING - Uncorrectable error in packet, 
> dropped.
> 2004-04-26 20:40:42 1       0
> 2004-04-26 20:40:42 1       0
> 2004-04-26 20:40:42 DVB#0 WARNING - Uncorrectable error in packet, 
> dropped.
> 2004-04-26 20:40:43 1       0
> 2004-04-26 20:40:43 DVB#0 WARNING - Uncorrectable error in packet, 
> dropped.
> 2004-04-26 20:40:43 DVB#0 WARNING - Uncorrectable error in packet, 
> dropped.
> 2004-04-26 20:40:43 1       0
> 2004-04-26 20:40:43 DVB#0 WARNING - Uncorrectable error in packet, 
> dropped.
> 2004-04-26 20:40:43 1       0
> 2004-04-26 20:40:43 1       0
> 2004-04-26 20:40:43 DVB#0 WARNING - Uncorrectable error in packet, 
> dropped.
> 2004-04-26 20:40:43 1       0
> 2004-04-26 20:40:44 1       0
> 2004-04-26 20:40:44 1       0
> 2004-04-26 20:40:44 1       0
> 2004-04-26 20:40:44 1       0
> 2004-04-26 20:40:44 DVB#0 WARNING - No data from card in 1 second.
> 2004-04-26 20:40:44 1       0
> 2004-04-26 20:40:45 1       0
> 2004-04-26 20:40:45 1       0
> 2004-04-26 20:40:45 1       0
> 2004-04-26 20:40:45 1       0
> 2004-04-26 20:40:45 DVB#0 WARNING - No data from card in 1 second.
> 2004-04-26 20:40:45 DVB#0 WARNING - Uncorrectable error in packet, 
> dropped.
> 2004-04-26 20:40:45 1       0
> 2004-04-26 20:40:46 DVB#0 WARNING - Uncorrectable error in packet, 
> dropped.
> 2004-04-26 20:40:46 1       0
> 2004-04-26 20:40:46 DVB#0 WARNING - Uncorrectable error in packet, 
> dropped.
>
> This happens with about 5-10% of channel changes. It just repeats the 
> last log
> entries forever so it requires restarting both backend and frontend in 
> order to
> recover, which is pretty irritating in the long run. It happens with 
> all
> channels that are available in the network. But when a stream is 
> flowing, it's
> never interrupted and picture is great etc. so it's stable when you 
> get it
> running. Problem only exists immediatelly after a channel change. Any 
> ideas
> what could be wrong? Or any hints if there're some timing settings or 
> something
> that I might try to tune in the source code and check if it helps (I'm 
> not
> afraid to hack and debug things, it's just that I don't have any 
> previous
> experience with MythTV codebase and DVB(-C) technology :)
>
> Thanks,
>
> -- 
> Tuomas Jormola <tjormola at cc.hut.fi>
> _______________________________________________
> mythtv-users mailing list
> mythtv-users at mythtv.org
> http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
>


-- 
Tuomas Jormola <tjormola at cc.hut.fi>



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