[mythtv-users] "Tuner 5 has an error"
mythtv at kosowsky.org
mythtv at kosowsky.org
Thu Apr 25 17:19:10 UTC 2019
Stephen Worthington wrote at about 22:50:51 +1200 on Thursday, April 25, 2019:
> On Thu, 25 Apr 2019 10:37:55 +0100, you wrote:
> >On 25/04/2019 05:06, mythtv at kosowsky.org wrote:
> >> I am using mythtv 29.1 under Ubuntu 18.04 running under kernel 5.0.9.
> >> I initially installed a Hauppauge WinTV-quadHD PC Express card that
> >> provides 4 dvb inputs:
> >> /dev/dvb/adapter0/frontend0
> >> /dev/dvb/adapter1/frontend0
> >> /dev/dvb/adapter2/frontend0
> >> /dev/dvb/adapter3/frontend0
> >> The Frontend ID for all is: LGDT3306A VSB/QAM Frontend.
> >> I then added a Hauppauge WinTV-HVR-955Q (aka Hauppauge Digital TV
> >> Tuner for Xbox One) USB tuner.
> >> That tuner is recognized by Linux as /dev/dvb/adapter4/frontend4.
> >> It works fine with VLC.
> >> Mythtv recognis the card appropriately as /dev/dvb/adapter4/frontend4
> >> with Frontend ID also LGDT3306A VSB/QAM Frontend.
> >> Everything seems fine, but I can't switch to the card input on LiveTV.
> >> System info says "Tuner 5 has an error" with details:
> >> Tuner 4 [DVB: /dev/dvb/adapter4/frontend0] has an error
> >> (Note numbering is off because I name them Tuner 0 through 4 whereas
> >> System info seems to count them 1 to 5,
> >> The mythtv-setup configuration for the tuner is the exact same as the
> >> other 4.
> >> When I cycle through the tuners on Live TV, I go from Tuner 0 to 1 to
> >> 2 to 3 and back to 0.
> >> (Note that when I type M->Source, I get only the first 3 tuners...)
> >> The syslog shows for each tuner switch (but no errors for the 'skipped' Tuner 4):
> >> Apr 24 23:49:03 consult kernel: [83954.235912] dvb_frontend: dvb_frontend_get_frequency_limits: frequency interval: tuner: 42000000...870000000, frontend: 54000000...858000000
> >> Apr 24 23:49:03 consult kernel: [83959.284003] dvb_frontend: dvb_frontend_get_frequency_limits: frequency interval: tuner: 42000000...870000000, frontend: 54000000...858000000
> >> Any hints on how to track down the 'error' for the last tuner.
> >> _______________________________________________
> >You can safely ignore the "dvb_frontend:
> >dvb_frontend_get_frequency_limits: ..." messages (they are due to an
> >omission in a V4L update, where they should only be output under debug
> >conditions, but the debug check line is missing).
> > From a clean boot the output "dmesg | grep frontend" from a terminal
> >session will show the order of detection and allocation to
> >Assuming that all required firmware files are in /lib/firmware/, my
> >initial guess (without seeing mythbackend.log) is that USB Tuner is not
> >completely initialised at mythtv-backend startup, so mythtv gives the
> >error message.
> >A quick check to see if this is the problem is to stop and start
> >mythtv-backend as follows in a terminal session:
> >sudo systemctl stop mythtv-backend
> >sudo systemctl start mythtv-backend
> >now using mythfrontend try LiveTV, If the error is no longer present it
> >means a race condition at startup
> >A quick and dirty fix, as an interim only, is to delay mythtv-backend
> >startup by a fixed time:
> >In a terminal on the machine running mythtv backend:
> >sudo systemctl edit mythtv-backend.service and add the following two lines:
> >ExecStartPre=/bin/sleep 20
> >Then exit from the edit screen (it uses nano by default, so Ctrl+x, then
> >y, then Return key) then reboot the machine
> >The real fix is more complicated, if the startup delay resolves your
> >issue there is more information at
> >see section on Delay starting the backend until tuners have initialized
> If you are right about the tuner taking too long to start up, then it
> is much better to go directly to the correct systemd fix rather than
> trying the dirty one that might not work. Here are specific
> instructions for the correct fix:
> First, create this file in /etc/udev/rules.d:
> root at mypvr:/etc/udev/rules.d# cat 99-tuner.rules
> # Create systemd device units for capture devices
> SUBSYSTEM=="video4linux", TAG+="systemd"
> SUBSYSTEM=="dvb", TAG+="systemd"
> SUBSYSTEM=="firewire", TAG+="systemd"
> The 99-tuner.rules file needs to have the right ownership and
> sudo chown root:root /etc/udev/rules.d/99-tuner.rules
> sudo chmod u=rw,g=r,o=r /etc/udev/rules.d/99-tuner.rules
> Then create a systemd override file for mythtv-backend:
> sudo systemctl edit mythtv-backend.service
> In the override file, put this:
> That will create a file
> /etc/systemd/system/mythtv-backend.service.d/override.conf. If you
> already have an override file in that directory with a different name,
> edit that and add the above to it.
> Then reboot.
> Now the mythtv-backend service will not be started until all those
> devices exist, or a long timeout (90 seconds, I think) happens. So if
> the USB tuner is unplugged or faulty, mythbackend will take a long
> time before it is started.
> You can see the status of the mythtv-backend service with this
> systemctl status mythtv-backend
If the problem were due to startup, wouldn't restarting mythtv-backend
manually well after boot(which I have tried multiple times) have solved this?
The devices presumably all exist and work fine since I have no problem
using the card under VLC. The dvb device even gets recognized properly
Just when I try to actually use the device, it shows an error on Tuner 5.
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