[mythtv-users] No /dev/dvb devices

R. G. Newbury newbury at mandamus.org
Mon Mar 19 19:26:29 UTC 2007

David Highley wrote:
> "R. G. Newbury wrote:"
>> Michael T. Dean wrote:
>>> On 03/18/2007 02:17 PM, Yeechang Lee wrote:
>>>> Anthony Messina <amessina at messinet.com> says:
>>>>> i have the same issue as the previous poster.  since it worked for
>>>>> you, would you mind sharing your /etc/modprobe.conf?
>>>> I don't have any HD5000-related entries in my /etc/modprobe.conf.
>>> OP just needs to load cx88-dvb through his distro's supplied automatic 
>>> module-loading scripts (i.e. /etc/modules or /etc/sysconfig/modules or 
>>> /etc/modprobe/cx88-dvb or ... --ask on your distro's fora/mailing lists) 
>>> or through an appropriate modprobe.conf entry (the first is easier than 
>>> the second approach).  Note, also, that Linux 2.6.21 will likely fix the 
>>> issue causing cx88-dvb to fail to load automatically, so doing things 
>>> incorrectly (i.e. through auto-module-loading scripts) for such a short 
>>> time is not a big deal.
>> The problem here is that the new kernel is *too* good. Previously these 
>> cards were not as well recognized, and at least in Fedora, the modprobe 
>> entry prevailed. Then in 2.1.18 or 19, the kernel started recognizing 
>> both the analog and digital sides, and loads a module, apparently at 
>> random. This also seems to lock the modula, so that modprobe -r does not 
>> work. This appears to happen BEFORE modprobe is run (Could be wrong but 
>> I don't think so.)
>> If the dvb side gets loaded first, the analog can be loaded later but 
>> apparently, not the other way round.
> That is not the way it worked for me with Fedora core 6. I had both the
> analog side of the HD3000 card and the PVR 500 devices created and the
> drivers loaded and then did a modprobe c88xx-dvb and all seemed to stay
> working.

Wow! I'm running fedora Core 6 as well. I cannot rememeber offhard which 
kernel is on the mythbox.

I must admit, I did not try just modprobing the cx88_dvb module in 
rc.local. But I did get a FATAL: Module in use error' when I tried to 
unload the cx8800 module in rc.local, preparatory to loading the 
cx88_dvb. That is why I blacklisted that module.

I assume, from what you write, that the system is happy with just 
loading the cxi88_dvb module in rc.local...which strongly implies that 
it should be happy to do that in modprobe.conf.

So when do you load mythbackend? Before or after the cx88_dvb install?

And if you have them both installed and running, can you change tuners 
back and forth to use both sides of the card. I suspect that there is a 
little bit of art and skill involved in getting this working and it 
should be figured out and documented. And I seriously think that it 
requires a quite recent kernel to make it work at all.

Personally, I have never actually tried to use the HD3000 card for 
analog reception, so my efforts have concentrated on getting rid of the 
analog module.


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