[mythtv] Problems with Hauppauge Nova TD Dual Tuner USB Stick and Mythtv, no problems in Windows!

[Stephen Worthington]

On Sat, 13 Apr 2013 23:23:35 +0100, you wrote:

>Another data point. I've been fighting my Nova TD ever since I upgraded to 
>Ubuntu 12.10 with MythTV 0.25.2. Well actually I've been fighting my TD ever 
>since I bought it, but before 12.10 I felt like I was winning.
>
>My memory fades, but I think the magic fix in the past was setting the 
>bandwidth to auto.  With 12.10/0.25 my MythTV log was full of auto bandwidth 
>not being a valid setting, so I changed to using 8MHz bandwidth and can now 
>occasionally get a lock, but mostly just end up with partial locks. 
>
>Interestingly, tzap has no trouble tuning:
>
>$ head -n1 channels.conf
>BBC ONE Scot:522000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_AUTO:FEC_AUTO:
>QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_32:HIERARCHY_NONE:101:102:4220
>
>$ tzap -c channels.conf "BBC ONE Scot"
>using '/dev/dvb/adapter0/frontend0' and '/dev/dvb/adapter0/demux0'
>reading channels from file 'channels.conf'
>tuning to 522000000 Hz
>video pid 0x0065, audio pid 0x0066
>status 0f | signal f9ee | snr 00d1 | ber 001fffff | unc 00000000 | 
>status 1f | signal ffff | snr 010f | ber 00000000 | unc 00000000 | FE_HAS_LOCK
>^C
>
>So something changed, but I'm still struggling to find out what.
>
>Good luck,
>Ed

There are options on drivers that can affect things.  You set them
from the /etc/modprobe.d directory.  My Hauppauge WinTV Nova TD-500
PCI dual tuner card has one that turns on the low noise amplifier.  It
is supposed to work automatically now, in current driver versions, but
in older drivers it had to be set manually, and caused problems
exactly like yours.  So maybe it is not turning on automatically and
needs to be forced on.

You can find the options for drivers by using the modinfo command. You
need to know the name of the driver - in my case, it is
dvb_usb_dib0700 so the command:

modinfo dvb_usb_dib0700

produces a big listing with these "parm" values at the end:

parm:           force_lna_activation:force the activation of
Low-Noise-Amplifyer(s) (LNA), if applicable for the device (default:
0=automatic/off). (int)
parm:           debug:set debugging level (1=info,2=fw,4=fwdata,8=data
(or-able)). (int)
parm:           nb_packet_buffer_size:Set the dib0700 driver data
buffer size. This parameter corresponds to the number of TS packets.
The actual size of the data buffer corresponds to this parameter
multiplied by 188 (def ault: 21) (int)
parm:           adapter_nr:DVB adapter numbers (array of short)

So putting a line like this in a file in /etc/modeprobe.d (eg
options-dvb.conf) would force my LNA on:

options dvb_usb_dib0700 force_lna_activation=1

Your driver name may be different - you can find a list of all the
driver names using a command like:

modprobe -l | grep dvb-usb

There is probably a way of finding driver names from /proc or /sys
somewhere (I have never figured that out), and the driver name should
show up in dmesg and kern.log when it is loaded.  This is from my
dmesg:

[   19.287457] usbcore: registered new interface driver
dvb_usb_dib0700

Some drivers also have debug options there that you can use to make
them tell you more about what they are doing.