[mythtv-users] Clunky tuner detection in mythtvsetup

[John Pilkington]

On 08/08/17 15:22, Stephen Worthington wrote:
> On Tue, 8 Aug 2017 10:52:18 +0100, you wrote:
> 
>> I have two devices with three DVB-T tuners on this box, running 30pre3
>> with the 4.4.79-1.el7.elrepo.x86_64 kernel.
>>
>> $ dmesg | grep adapt
>> [   18.492232] DVB: registering new adapter (Kworld UB499-2T T09)
>> [   18.497274] usb 1-1: DVB: registering adapter 1 frontend 0 (Afatech
>> AF9033 (DVB-T))...
>> [   18.500472] DVB: registering new adapter (Kworld UB499-2T T09)
>> [   18.516789] usb 1-1: DVB: registering adapter 2 frontend 0 (Afatech
>> AF9033 (DVB-T))...
>> [   20.417032] DVB: registering new adapter (saa7133[0])
>> [   20.417041] saa7134 0000:07:04.0: DVB: registering adapter 0 frontend
>> 0 (Philips TDA10046H DVB-T)...
>>
>> The adapter error rates vary, 0 being the best and 2 the worst.  I aim
>> to have multirec settings of 8, 5, 5.  I have had this in the past but
>> recent trials had upset things;  yesterday I saw a gap in the schedule
>> and tried to improve matters.  It was a frustrating experience and I'm
>> not yet sure that I got what I wanted: a simple and logical assignment
>> of 'virtual tuner' numbers.
>>
>> The card identification process showed the type but probing often failed
>> to show the device identifier, and restarts always involved lengthy
>> searches for disecq trees and upnp devices like VBox, which I know I
>> don't have.  The kernel identified my hardware soon after boot.
>>
>> There was some work on this sort of thing at Ticket #12547 but setup is
>> typically done once and then forgotten.  Have I missed some shortcuts?
>>
Stephen:  Thanks for your very comprehensive reply.  Well worth reading 
although I've cut it here.

Multirec can be > 5 in master - the higher value gets used mainly by my 
radio recordings.

I have a dvb.conf file which works with that el7.elrepo kernel but 
didn't the last time I used a standard el7 kernel.

I suspect that some of my dropped or misplaced packets happen because 
trees are growing on my sight line and the pci-card or its driver just 
copes better.  Everything comes through the same aerial and preamp, with 
various splitters after.  Do you have away of detecting buffer-overruns?

I did edit the DB entries when code changes lost multirec early last 
year, and I may well try it now, but it's not a good general solution.
And I did consider clearing everything for a fresh start - but was 
initially hoping for a quick fix.

I had the impression that the disecq and upnp delays were going up with 
my multirec numbers.  I've found some of the code but as yet it's not 
entirely clear...

Cheers,

John