[mythtv-users] Udev

[Ian Campbell]

On Tue, 2018-11-27 at 08:17 -0500, Daryl McDonald wrote:
> In  previous set up with two sources, and cards staying in the same
> slots, enumeration would, on occasion, be different. Stephan, are you
> saying that is now different?
> Of four tuners, there will be one HP1250, one HP winTV, and two
> PCi800's, the last two of which may have no differences, but I may
> try and find some (for hind-sight diagnostics)

Even in the absence of USB devices masquerading as PCI cards the
loading of drivers, and therefore the binding of driver→device, is
asynchronous, and therefore the assignment of DVB adapter IDs can vary
depending on the order they get discovered in.

Personally I deal with this using module options rather than udev:
   # cat /etc/modprobe.d/dvb-usb-dib0700.conf 
   options dvb-usb-dib0700 adapter_nr=0,1,2,3
   options em28xx-dvb adapter_nr=4,5,6,7

This ensures that adaptors 0-3 are always the dib0700 ones and adaptors
4-7 are always the em28xx ones, but makes no guarantee about which
dib0700 will be adaptor #3 etc. That's all I care about because the
em28xx ones are HD capable while the dib0700 ones are not.

This works well enough for me, but it does mean that if one adaptor is
flakey then it can switch around (within its corresponding set of ids)
on reboot.

If your three classes of card use three different drivers then you
ought to be able to arrange that the HP1250=adaptor#0, the
winTV=adaptor#1 and the PCi800's are #2 and #3 (in some order).

Ian.