Re: [PATCH 0/5] isdn: deprecate non-mISDN drivers

> > Where mISDN and CAPI can be used in combination.
>
> Can you elaborate on how those are combined? The supported hardware
> for mISDN (HFC, fritz!card PCI, Seldbaur Speedfax, ...) and CAPI (AVM b1,

You can use CAPI on top of mISDN. But as has been pointed out, that might
take another route. I'm not in to the CAPI stuff.
Can anyone confirm if that combination uses the kernel CAPI interface or not?
If it doesn't, the CAPI stuff would seem more obsolete to me than I4L.

> Can you point to a specific installation that uses those obsolete drivers
> on modern kernels? Generally I would assume that any installation
> that is conservative enough to still rely on those drivers would have
> long ago stopped upgrading major kernel versions.

I have it installed on all our voice application servers for the reason of
being able to use divertctrl even if they are running mISDN in normal
operation. It's more than ugly, but better than nothing at all.
The machines are currently running 4.9, but I need to upgrade to be able
to use currently available mainboards.

> The last time that anyone seems to have actually done any isdn4linux
> development appears to be in 2012 when Jiri Slaby sent a series of
> cleanups for the the tty code, but it's not entirely clear if he tested it.

I have to admit I haven't done any extensive testing, but I certainly din't
notice any bugs.
I know it may seem unimaginable in our modern times, but did it ever occour
to you that maybe it isn't being changed because it just works as intended?

Thare had been a suggestion at our hackerspace to set up some BBS systems so
that people could experience how things worked in the old days.
Maybe I should take up on that idea and add some ipppd dial-in to that.
Even if it's just to confirm that it actually still works.

> There is exactly one version of mISDN in the mainline kernel. Any other
> version is meaningless to this discussion.

If it's about things being maintained or not, I see that as quite important.
Maybe the issue is not that tings are not being maintained, but rather that
the efforts don't make it upstream for whatever reason outside the scope
of this discussion?

> This is easily solved by removing I4L ;-)

Removing working things, does not seem like a good idea to me.
We still have floppy support and I guess they have a lot less use.

> Could you be more specific which hardware you still see being used with
> CAPI+hylafax? Is it all the avmb1 driver, or also the other ones (gigaset,
> hysdn, cmtp)?

Any mISDN hardware, see above.
There was a thread here on the ML about that when it came up.

> How much longer do you expect to need it?

At least as long as the ISDN is running and being used.
And I expect that to be quite some more years.

> SLES15 and RHEL8 will have
> 4.x kernels for many years to come, and even Ubuntu 18.04 will still
> get updates until 2023.

But you won't get support for current hardware then.

  Greetings,
    WIMPy