Merge tag 'isdn-removal' of https://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground

Arnd Bergmann says:

====================
isdn: deprecate non-mISDN drivers

When isdn4linux came up in the context of another patch series, I
remembered that we had discussed removing it a while ago.

It turns out that the suggestion from Karsten Keil wa to remove I4L
in 2018 after the last public ISDN networks are shut down. This has
happened now (with a very small number of exceptions), so I guess it's
time to try again.

We currently have three ISDN stacks in the kernel: the original
isdn4linux (with the hisax driver), the newer CAPI (with four drivers),
and finally the mISDN stack (supporting roughly the same hardware as
hisax).

As far as I can tell, anyone using ISDN with mainline kernel drivers in
the past few years uses mISDN, and this is typically used for voice-only
PBX installations that don't require a public network.

The older stacks support additional features for data networks, but those
typically make no sense any more if there is no network to connect to.

My proposal for this time is to kill off isdn4linux entirely, as it seems
to have been unusable for quite a while. This code has been abandoned
for many years and it does cause problems for treewide maintenance as
it tends to do everything that we try to stop doing.
Birger Harzenetter mentioned that is is still using i4l in order to
make use of the 'divert' feature that is not part of mISDN, but has
otherwise moved on to mISDN for normal operation, like apparently
everyone else.

CAPI in turn is not quite as obsolete, but two of the drivers (avm
and hysdn) don't seem to be used at all, while another one (gigaset)
will stop being maintained as Paul Bolle is no longer able to
test it after the network gets shut down in September.
All three are now moved into drivers/staging to let others speak
up in case there are remaining users.
This leaves Bluetooth CMTP as the only remaining user of CAPI, but
Marcel Holtmann wishes to keep maintaining it.

For the discussion on version 1, see [2]
Unfortunately, Karsten Keil as the maintainer has not participated in
the discussion.

      Arnd

[1] https://patchwork.kernel.org/patch/8484861/#17900371
[2] https://listserv.isdn4linux.de/pipermail/isdn4linux/2019-April/thread.html
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 0 insertions, 51 deletions

diff --git a/drivers/isdn/Kconfig b/drivers/isdn/Kconfig
index 1ca4d70d198a..be8387c0eeef 100644
--- a/drivers/isdn/Kconfig
+++ b/drivers/isdn/Kconfig
@@ -21,59 +21,8 @@ menuconfig ISDN
 
 if ISDN
 
-menuconfig ISDN_I4L
-	tristate "Old ISDN4Linux (deprecated)"
-	depends on TTY
-	---help---
-	  This driver allows you to use an ISDN adapter for networking
-	  connections and as dialin/out device.  The isdn-tty's have a built
-	  in AT-compatible modem emulator.  Network devices support autodial,
-	  channel-bundling, callback and caller-authentication without having
-	  a daemon running.  A reduced T.70 protocol is supported with tty's
-	  suitable for German BTX.  On D-Channel, the protocols EDSS1
-	  (Euro-ISDN) and 1TR6 (German style) are supported.  See
-	  <file:Documentation/isdn/README> for more information.
-
-	  ISDN support in the linux kernel is moving towards a new API,
-	  called CAPI (Common ISDN Application Programming Interface).
-	  Therefore the old ISDN4Linux layer will eventually become obsolete.
-	  It is still available, though, for use with adapters that are not
-	  supported by the new CAPI subsystem yet.
-
-source "drivers/isdn/i4l/Kconfig"
-
-menuconfig ISDN_CAPI
-	tristate "CAPI 2.0 subsystem"
-	help
-	  This provides CAPI (the Common ISDN Application Programming
-	  Interface) Version 2.0, a standard making it easy for programs to
-	  access ISDN hardware in a device independent way. (For details see
-	  <http://www.capi.org/>.)  CAPI supports making and accepting voice
-	  and data connections, controlling call options and protocols,
-	  as well as ISDN supplementary services like call forwarding or
-	  three-party conferences (if supported by the specific hardware
-	  driver).
-
-	  Select this option and the appropriate hardware driver below if
-	  you have an ISDN adapter supported by the CAPI subsystem.
-
-if ISDN_CAPI
-
 source "drivers/isdn/capi/Kconfig"
 
-source "drivers/isdn/hardware/Kconfig"
-
-endif # ISDN_CAPI
-
-source "drivers/isdn/gigaset/Kconfig"
-
-source "drivers/isdn/hysdn/Kconfig"
-
 source "drivers/isdn/mISDN/Kconfig"
 
-config ISDN_HDLC
-	tristate
-	select CRC_CCITT
-	select BITREVERSE
-
 endif # ISDN