Opened 15 years ago
Closed 14 years ago
Last modified 13 years ago
#7198 closed defect (invalid)
DVB tuning fails with HVR-1300 on Linux kernels starting with 2.6.27
Reported by: | Owned by: | Janne Grunau | |
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Priority: | minor | Milestone: | unknown |
Component: | MythTV - DVB | Version: | head |
Severity: | medium | Keywords: | hvr-1300 tuning |
Cc: | linux@… | Ticket locked: | no |
Description
Hi,
after upgrading my Linux kernel on my Debian box running mythTV from 2.6.26 to 2.6.30 DVB tuning would fail with 'could not get signal lock', no matter which channel I tried. I tried different kernels and it seems the problem starts with 2.6.27 and get worse with 2.6.28 and the following.
I tried tuning with kaffeine and it does not find all but most of the channels. tzap can lock all channels.
I have attached the output of the current head revision in trunk for mythtv-setup given a single input channel on both 2.6.26 and 2.6.31-rc7 as well as the tzap output on 2.6.31-rc7 to illustrate the problem.
Please let me know if you need further info.
Thanks and best wishes,
Martin.
Attachments (7)
Change History (15)
Changed 15 years ago by
Attachment: | mythtv-setup-2.6.31-rc7-edited.log added |
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Changed 15 years ago by
Attachment: | mythtv-setup-2.6.26-edited.log added |
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channel tuning output on Linux kernel 2.6.26
Changed 15 years ago by
Attachment: | mythtv-setup-2.6.26-edited.2.log added |
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channel tuning output on Linux kernel 2.6.26
Changed 15 years ago by
Attachment: | tzap-2.6.31-rc7.log added |
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tzap output for same channel on 2.6.31
comment:1 follow-up: 3 Changed 14 years ago by
Status: | new → infoneeded_new |
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strange, I would say a kernel bug. Please check the frontend status during the scan with femon. if it's is never FE_HAS_LOCK, please attach tzap's channels.conf. I suspect a difference in the parameters. You could also check scanning with more parameters set to auto.
Changed 14 years ago by
Attachment: | femon-mythtv added |
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femon output from MythTV scanning of one multiplex
Changed 14 years ago by
Attachment: | channelscan-scan-7198.txt added |
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channels file made with scan, used as input to tzap tuning
comment:2 Changed 14 years ago by
I have a HVR-4000, but the DVB-T part seems to be equal: From mythtv-setup-2.6.31-rc7-edited.log: 2009-09-28 20:58:07.024 DVBChan(4:/dev/dvb/adapter0/frontend0): Using DVB card /dev/dvb/adapter0/frontend0, with frontend 'Conexant CX22702 DVB-T'. From my scan: 2009-10-08 00:37:05.451 DVBChan(1:/dev/dvb/adapter0/frontend1): Using DVB card /dev/dvb/adapter0/frontend1, with frontend 'Conexant CX22702 DVB-T'. So I hope these logs are relevant.
comment:3 follow-up: 4 Changed 14 years ago by
Replying to janne:
strange, I would say a kernel bug. Please check the frontend status during the scan with femon. if it's is never FE_HAS_LOCK,
A funny thing happened:
- when I start femon and then start the channel scan I get a lock and all channels are found
- However, when I run the channel scan without having femon running at the same time no channel gets found
- If a channel is being scanned and I start femon then, still nothing is found.
Could it be that femon does some initialization on the adapter that is missing in otherwise?
please attach tzap's channels.conf. I suspect a difference in the parameters. You could also check scanning with more parameters set to auto.
I have actually been using the same channels.conf for both mythtv-setup and tzap during my testing so there is no difference.
Thanks for your help and best wishes,
Martin.
comment:4 follow-up: 5 Changed 14 years ago by
Status: | infoneeded_new → new |
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Replying to linux@martin-kittel.de:
- when I start femon and then start the channel scan I get a lock and all channels are found
- However, when I run the channel scan without having femon running at the same time no channel gets found
- If a channel is being scanned and I start femon then, still nothing is found.
strange
Could it be that femon does some initialization on the adapter that is missing in otherwise?
I don't think so, but I'll look what femon does exactly.
I have actually been using the same channels.conf for both mythtv-setup and tzap during my testing so there is no difference.
could you test the full scan germany?
There is a bug in the kernel for the HVR-1300/4000 which seems to be related
https://bugs.launchpad.net/mythtv/+bug/439163
it should only affect 2.6.29+ though
comment:5 Changed 14 years ago by
Replying to janne:
could you test the full scan germany?
I tried with 2.6.31 vanilla and again had the same problem: if femon was started before mythtv-setup, the scan was ok, if started femon at a later time, no channels were found.
There is a bug in the kernel for the HVR-1300/4000 which seems to be related
I have tried the patch/revert to cx88-dvb.c mentioned in that thread and that seems to do the trick for me as well. I can watch TV again. For now it seems that tuning takes a bit longer than before because I get the channel lock warning which I did not see with earlier kernels. After a few seconds, however, the picture appears. I will keep an eye on this.
BTW, http://svn.mythtv.org/trac/ticket/7292 seems to be about the same issue.
it should only affect 2.6.29+ though
Judging from the time the change was made it could have been 2.6.27 as well, but I am no git expert and cannot determine when it actually went into mainline.
What is the correct way to proceed now? Wait for a kernel patch?
In any case, thanks for your help!
comment:6 Changed 14 years ago by
Hi,
I just checked: the problem is fixed in 2.6.32, so this bug can be closed.
Best wishes,
Martin.
comment:7 Changed 14 years ago by
Resolution: | → invalid |
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Status: | new → closed |
comment:8 Changed 13 years ago by
The real bug seems to be found. The other solution is now obsolete. Hope this gets into kernel quick.
How can i prevent that post to fall in the spam filter .... maybe by this line (Did help on the other ticket:) ) This time i need to add some more text it seems.
channel tuning output on Linux kernel 2.6.31