DVB tuner suddenly "successfully deinitialized and disconnected"

Benjamin Arnold

rPI running Tvheadend with a (fairly generic) RTL2832 USB tuner. Up until yesterday this was working fine. Today I rebooted it and now the tuner doesn't work. Running "dmesg | grep dvb" brings up the following:

[ 17.962539] usb 1-1.5.4: dvb_usb_v2: found a 'Trekstor DVB-T Stick Terres 2.0' in warm state
[ 18.048737] usb 1-1.5.4: dvb_usb_v2: will pass the complete MPEG2 transport stream to the software demuxer
[ 18.048813] dvbdev: DVB: registering new adapter (Trekstor DVB-T Stick Terres 2.0)
[ 18.423711] rc rc0: lirc_dev: driver dvb_usb_rtl28xxu registered at minor = 0, raw IR receiver, no transmitter
[ 18.438064] usb 1-1.5.4: dvb_usb_v2: schedule remote query interval to 200 msecs
[ 18.473407] usb 1-1.5.4: dvb_usb_v2: 'Trekstor DVB-T Stick Terres 2.0' successfully initialized and connected
[ 18.474563] usbcore: registered new interface driver dvb_usb_rtl28xxu

[ 36.518061] dvb_usb_v2: 'Trekstor DVB-T Stick Terres 2.0:1-1.5.4' successfully deinitialized and disconnected

So it appears to be registering, and at that point /dev/dvb/adapter0 exists. But then 20 seconds later it decides to de-register it, and /dev/dvb vanishes.

If I physically disconnect and reconnect the USB tuner, same thing happens. And same thing after either a warm or cold restart of the rPI (and USB hub).

Has anybody seen anything like this before?

Thanks!

Benjamin Arnold

To follow up, it still shows on "lsusb"

pi@mash:/usr/lib $ lsusb
Bus 001 Device 005: ID 1f4d:c803 G-Tek Electronics Group
Bus 001 Device 004: ID 05e3:0608 Genesys Logic, Inc. Hub
Bus 001 Device 003: ID 0424:ec00 Standard Microsystems Corp. SMSC9512/9514 Fast Ethernet Adapter
Bus 001 Device 002: ID 0424:9514 Standard Microsystems Corp. SMC9514 Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

Benjamin Arnold

Getting the same with a more "reference" RTL2832

[ 39.177528] dvb_usb_v2: 'Realtek RTL2832U reference design:1-1.5.3' successfully deinitialized and disconnected

Sylvia Else

I have spent a couple of hours on this, and determined that in my case, the tuner gets disconnected because the random number generator daemon (rngd) wants to use use its software defined radio capability to obtain radio atmospheric noise as a random number source. Unfortunately, after its done that it doesn't revert to being a recognized DVB tuner.

My solution was to include the option -x rtlsdr on the rngd start line, which in my case was in /lib/systemd/system/rngd.service, but mileage will vary depending on the Linux distribution.

Seems a bit of a gotcha to let rngd do that by default in a distribution.