On Mon, Sep 25, 2017 at 10:16:23AM +1000, Eyal Lebedinsky wrote: > >Turn on debug printing for the modules of interest > ># echo 'module rtl2832 +p' > /sys/kernel/debug/dynamic_debug/control > ># echo 'module dvb_usb_rtl28xxu +p' > /sys/kernel/debug/dynamic_debug/control > > Have done this. Attached are the messages from a (failed) scandvb that fails for all multiplexes. > > The messages at the end continued at a high rate after the test finished (until I disabled debug > with '-p') and there was no user of the tuners. Maybe IR RC is active? This looks like progress, now we can see more of the rather odd behaviour. The tuned frequency does not progress monotonically, but wanders up and down the band. Frequency Delta 219166666 184833334 -34333332 191833334 7000000 191166666 -666668 177833334 -13333332 184166666 6333332 177166666 -7000000 191500000 14333334 184500000 -7000000 191833334 7333334 191166666 -666668 177500000 -13666666 219500000 42000000 184833334 -34666666 191500000 6666666 177833334 -13666666 184166666 6333332 191833334 7666668 191166666 -666668 177166666 -14000000 191500000 14333334 184500000 -7000000 177500000 -7000000 177833334 333334 177166666 -666668 The bandwidth and inversion type seem to be set correctly, at least. Also: - every instance of if_frequency=0 pset_iffreq=00000000 shows the same numbers - zero. Surely that can't be right. - there seems to be no correlation at all between the AGC level (automatic gain control, I assume) and the 'cnr raw' which I'm guessing is some measure of the signal level. I don't know where to start with decoding the rtl28xxu_ctrl_msg I'm afraid. It's quite possible the remote control is active. You can run ir-keytable -v to show which remotes the system knows about. We might get more clues to rub together from looking at where scandvb falls over, if you run it under 'strace' strace -t -s 2048 -o ./scandvb.strace scandvb <arguments here> This will show the system calls being made. The -t will add timestamps to the output that could be correlated with the dmesg output. I'm curious - did you try scandvb with one of your other tuners? I'm actually not familiar with scandvb, I can't find a program with that name in the ubuntu repositories. What I've used before is dvbv5-scan, which is part of: git://linuxtv.org/v4l-utils.git That repo also includes the v4l2-compliance tool, which might be useful here. Something like: ./v4l2-compliance -d /dev/dvb/adapter3 -a -T -v What I am not sure about is whether the tuner needs to be 'zapped' to a nice strong TV channel before you can use this. Anyway, hope some of these ideas are helpful. Cheers Vince
