[mythtv-users] AF9015 Dual tuner i2c write failures

William Kenworthy billk at iinet.net.au
Thu Nov 10 23:27:34 UTC 2011

On Fri, 2011-11-11 at 08:45 +1000, David Whyte wrote:
> On Fri, Nov 11, 2011 at 8:12 AM, Thomas Boehm
> <mythtv-users at lists.boehmi.net> wrote:
> > That's what I meant above. Shut down your PC completely. If your USB
> > ports are still powered after a shutdown, look in your BIOS to power
> > them down.
> >
> In the past with my tuners based on these chips, I had to really power
> off the server.  I would shutdown the OS, remove power from the PSU,
> try to turn on the PC (the fans would turn momentarily), scratch my
> head for 30seconds, just to be sure there is no power in the system,
> replace power lead and boot up.
> This forces the tuner chip to boot from 'cold, which will include a
> reload of the firmware.  If it is doing a 'warm' boot, it already has
> the firmware and doesn't reload it.
> You should see messages in dmesg which relate to 'dvb' or 'DVB' and
> indicate whether it is a warm or cold boot.

I have two usb thingies using this chip with gentoo - this might give
some clues.

I power off (at the mains via a remote switch every night, the machine
hibernates to disk.  If the signal is weak/not present at the chip
antenna, they often will not come back online.  Also, if mythbackend is
running when the machine is un-hibernating (is that a word :), the chip
wont initialise.

Fix for me is to stop mythbackend, remove all modules loaded when
inserted (tda18218,af9013,dvb_usb_af9015), make sure the signal is ok
then reload modules and restart mythbackend

Its not having a signal present when its loading up that seems to be the
root cause of most problems - but its pretty random, works a few times
then just refuses until until the modules are reloaded.  In a very few
cases, pulling/reinserting the usb key is needed as well but having a
reliable signal when coming online was the main "fix".


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