DVB scan fails to find channels / Timeout Scanning -- no tables

[kickus]

My mythtv is not able to lock to a stream, which makes both the LiveTV and recording functions unusable. However, the mythtv is able to scan for channels (and finds them).

I've earlier tried 0.18 and was hoping that the problems would have been solved in 0.19, but unfortunately the problem persists. My drivers should be ok since kaffeine works very nice.

When trying to activate LiveTV in the frontend, I get an error message "You should have gotten a channel lock by now. You can continue to wait for a signal, or you can change the channels with Up or Down, change input's (C), capture cards (Y), etc."

Here is a snippet of the mythtv output:

2006-02-19 18:46:46.071 TV: Changing from None to WatchingLiveTV
2006-02-19 18:46:46.123 Realtime priority would require SUID as root.
2006-02-19 18:46:47.321 Video timing method: USleep with busy wait
2006-02-19 18:47:22.701 rebuffering (22929 32768)
2006-02-19 18:47:23.626 NVP: prebuffering pause
2006-02-19 18:47:24.465 NVP: Prebuffer wait timed out 10 times.
2006-02-19 18:47:25.305 NVP: Prebuffer wait timed out 10 times.
2006-02-19 18:47:26.145 NVP: Prebuffer wait timed out 10 times.
2006-02-19 18:47:26.985 NVP: Prebuffer wait timed out 10 times.
2006-02-19 18:47:27.825 NVP: Prebuffer wait timed out 10 times.
2006-02-19 18:47:28.414 rebuffering (12529 32768)
2006-02-19 18:47:28.665 NVP: Prebuffer wait timed out 10 times.
2006-02-19 18:47:29.506 NVP: Prebuffer wait timed out 10 times.
2006-02-19 18:47:29.757 rebuffering (1 32768)
0: start_time: 857.475 duration: -9223372036854.775
stream: start_time: 9527.500 duration: -9223372036854.775 bitrate=0 kb/s
2006-02-19 18:47:30.350 NVP: Prebuffer wait timed out 10 times.
2006-02-19 18:47:30.777 AFD: Opened codec 0x841bca0, id(MPEG2VIDEO)
type(Video) 2006-02-19 18:47:30.777 NVP: Disabling Audio, params(0,-1,-1)
2006-02-19 18:47:31.190 NVP: Prebuffer wait timed out 10 times.

I'm running linux 2.6.15.4 and I'm using debian sid with the latest mythtv-packages from ​ftp://ftp.nerim.net/debian-marillat (at the moment version 0.19-0.2).

My Cinergy 1400 (dvb-t) card reports:

0000:00:0e.0 Multimedia video controller: Conexant CX23880/1/2/3 PCI Video and Audio Decoder (rev 05)

Subsystem: TERRATEC Electronic GmbH: Unknown device 1166 Flags: bus master, medium devsel, latency 64, IRQ 3 Memory at fc000000 (32-bit, non-prefetchable) [size=16M] Capabilities: [44] Vital Product Data Capabilities: [4c] Power Management version 2

0000:00:0e.2 Multimedia controller: Conexant CX23880/1/2/3 PCI Video and Audio Decoder [MPEG Port] (rev 05)

Subsystem: TERRATEC Electronic GmbH: Unknown device 1166 Flags: bus master, medium devsel, latency 64, IRQ 3 Memory at fd000000 (32-bit, non-prefetchable) [size=16M] Capabilities: [4c] Power Management version 2

What might have gone wrong?

[kickus]

I forgot to tell about the syslog output:

Feb 19 18:46:33 localhost kernel: cx88[0]/2: [ef04d780/0] cx8802_buf_queue - first active
Feb 19 18:46:33 localhost kernel: cx88[0]/2: cx8802_restart_queue
Feb 19 18:46:33 localhost kernel: cx88[0]/2: cx8802_restart_queue: queue is empty
Feb 19 18:46:33 localhost kernel: cx88[0]/2: queue is empty - first active
Feb 19 18:46:33 localhost kernel: cx88[0]/2: cx8802_start_dma w: 0, h: 0, f: 2
Feb 19 18:46:33 localhost kernel: cx88[0]/2: setting the interrupt mask
Feb 19 18:46:33 localhost kernel: cx88[0]/2: [ef04d6c0/0] cx8802_buf_queue - first active
Feb 19 18:47:19 localhost kernel: cx88[0]/2: cx8802_restart_queue
Feb 19 18:47:19 localhost kernel: cx88[0]/2: cx8802_restart_queue: queue is empty
Feb 19 18:47:19 localhost kernel: cx88[0]/2: queue is empty - first active
Feb 19 18:47:19 localhost kernel: cx88[0]/2: cx8802_start_dma w: 0, h: 0, f: 2
Feb 19 18:47:19 localhost kernel: cx88[0]/2: setting the interrupt mask
Feb 19 18:47:19 localhost kernel: cx88[0]/2: [ef04d780/0] cx8802_buf_queue - first active
Feb 19 18:47:31 localhost kernel: cx88[0]/2: cx8802_restart_queue
Feb 19 18:47:31 localhost kernel: cx88[0]/2: cx8802_restart_queue: queue is empty
Feb 19 18:47:31 localhost kernel: cx88[0]/2: queue is empty - first active
Feb 19 18:47:31 localhost kernel: cx88[0]/2: cx8802_start_dma w: 0, h: 0, f: 2
Feb 19 18:47:31 localhost kernel: cx88[0]/2: setting the interrupt mask
Feb 19 18:47:31 localhost kernel: cx88[0]/2: [ef04d6c0/0] cx8802_buf_queue - first active
Feb 19 18:48:09 localhost kernel: cx88[0]/2: cx8802_restart_queue
Feb 19 18:48:09 localhost kernel: cx88[0]/2: cx8802_restart_queue: queue is empty
Feb 19 19:00:01 localhost kernel: cx88[0]/2: queue is empty - first active
Feb 19 19:00:01 localhost kernel: cx88[0]/2: cx8802_start_dma w: 0, h: 0, f: 2
Feb 19 19:00:01 localhost kernel: cx88[0]/2: setting the interrupt mask
Feb 19 19:00:01 localhost kernel: cx88[0]/2: [ef04d780/0] cx8802_buf_queue - first active

/Kristian

[danielk]

Please attach a backend log with 'mythbackend -v record,siparser,channel' and a frontend log with 'mythfrontend -v playback' when tuning to a channel the scanner inserted.

Please make sure you delete your existing channels before you do the channel scan.

[kickus]

Sorry - I appearently didn't test well enough before reporting, since the channel scanner doesn't seem to find channels in 0.19 anymore. The 0.18 was able to find channels for me, but the 0.19 says:

Timeout Scanning -- no signal
Timeout Scanning -- no signal
Skipping CH_1 - not a Television or Radio Service
Skipping CH_2 - not a Television or Radio Service
Skipping CH_3 - not a Television or Radio Service
...
Timeout Scanning -- no tables
Timeout Scanning -- no signal
..and so on..

What is the "no signal" thing? I've got clear enough signal for other apps.

However, I restored the channels (tuned by 0.18) from my db-backup, to be able to record the logfiles as you mentioned. I don't know if you're interested in them since the channels are not scanned with 0.19.

Should this ticket really be closed already? Is there a solution for my problem?

[kickus]

Backend log

[kickus]

Frontend log

[kickus]

The 0.19 is not able to find channels, neither can it use the existing channels found and stored to db with the 0.18 scanner.

[danielk]

Ask on the mythtv-users how to scan for channels

[hoelli@…]

I have a problem similat to this e.g. with the same error messages in my logs. To me it seems to be some Problem with the cx88 kernel-module.

There is a fix for the kernel-module at ​http://linuxtv.org/~mkrufky/pending/jelle-cx88-mpeg-restart-queue-fix.patch which seems to make it slightly better. So the only hope will be new modules I think.

Perhaps someone will give this a try?

[danielk]

Hoelli, thanks for the info. It's not really a MythTV issue so I'm closing the ticket.

But for the original reporter, I did some more research on this. It looks like if you downgrade the kernel to 2.5.11, or apply the patch to a later kernel you have a good chance of squashing this problem. Changing the PCI slot has also been reported to work.

The problem with the driver appears to be triggered by the timing of tuning commands, which may explain why 0.18 would work when 0.19 does not. In svn head, you can change tuning slowdown pause in the "Recording Options" dialog for the card, plugging random numbers into this config option can let you work around these types of problems in the driver.

I've heard from the DVB driver folks that these types of problems are often due to reversed engineered drivers where the required sleep after each type of i2c command is unknown, and the driver devs use too small a value.