On 25/09/17 23:24, Vincent McIntyre wrote:
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
Grabbed the repo and built it. After some tries (I did not find enough doco)
I ran:
$ cat scan.in
T 177500000 7MHz 3/4 3/4 QAM64 8k 1/16 NONE
T 184500000 7MHz 2/3 1/2 QAM64 8k 1/8 NONE
T 191500000 7MHz 3/4 2/3 QAM64 8k 1/16 NONE
T 219500000 7MHz 3/4 3/4 QAM64 8k 1/16 NONE
T 226500000 7MHz 3/4 1/2 QAM64 8k 1/16 NONE
# the above is the usual frequencies table that I usually use successfully.
$ utils/dvb/dvbv5-scan -I CHANNEL --lna=0 scan.in
Lock (0x1f) Signal= 93.33% C/N= 16.62dB postBER= 17.5x10^-3
ERROR dvb_read_sections: no data read on section filter
ERROR error while waiting for PAT table
Scanning frequency #2 184500000
Lock (0x1f) Signal= 93.73% C/N= 20.09dB postBER= 65.5x10^-3
ERROR dvb_read_sections: no data read on section filter
ERROR error while waiting for PAT table
Scanning frequency #3 191500000
(0x00)
Scanning frequency #4 219500000
Lock (0x1f) Signal= 96.86% C/N= 20.29dB postBER= 65.5x10^-3
ERROR dvb_read_sections: no data read on section filter
ERROR error while waiting for PAT table
Scanning frequency #5 226500000
Lock (0x1f) Signal= 93.33% C/N= 19.66dB postBER= 19.6x10^-3
ERROR dvb_read_sections: no data read on section filter
ERROR error while waiting for PAT table
I also tried lna=0 and -1, same output.
That repo also includes the v4l2-compliance tool,
which might be useful here. Something like:
./v4l2-compliance -d /dev/dvb/adapter3 -a -T -v
Did not manage to run this:
$ utils/v4l2-compliance/v4l2-compliance -d /dev/dvb/adapter0 -a -T -v
Failed to open /dev/dvb/adapter0: Is a directory
$ ls -l /dev/dvb/adapter0/
total 0
crw-rw----+ 1 root video 212, 0 Sep 25 23:30 demux0
crw-rw----+ 1 root video 212, 1 Sep 25 23:30 dvr0
crw-rw----+ 1 root video 212, 3 Sep 25 23:30 frontend0
crw-rw----+ 1 root video 212, 2 Sep 25 23:30 net0
I need to find more doco on how to use this utility.
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
cheers
--
Eyal Lebedinsky (eyal@xxxxxxxxxxxxxx)
