kernel/git/stable/linux.git/Documentation/isdn/interface_capi.rst, branch master

net: remove ISDN subsystem and Bluetooth CMTP

2026-04-23T17:24:02+00:00

Remove the ISDN (mISDN, CAPI) subsystem and Bluetooth CMTP protocol from the kernel tree. ISDN is a pretty old technology and it's unclear whether anyone still uses it. I went over the last few years of git history and all the commits are either tree-wide conversions or syzbot/static analyzer fixes. When we discussed removal in the past IIRC there were some concerns about ISDN still being used in parts of Germany. Unfortunately, the code base is quite old, none of the current maintainers are familiar with it and AI tools will have a field day finding bugs here. Delete this code and preserve it in an out-of-tree repository for any remaining users: https://github.com/linux-netdev/mod-orphan UAPI constants AF_ISDN/PF_ISDN and the SELinux isdn_socket class are preserved for ABI stability, but the rest of uAPI is removed. Signed-off-by: Jakub Kicinski Acked-by: Greg Kroah-Hartman Acked-by: Stephen Hemminger Acked-by: Luiz Augusto von Dentz Reviewed-by: Simon Horman Link: https://patch.msgid.link/20260421022108.1299678-1-kuba@kernel.org Signed-off-by: Paolo Abeni

Documentation: isdn: correct spelling

2023-02-11T00:28:13+00:00

Correct spelling problems for Documentation/isdn/ as reported by codespell. Signed-off-by: Randy Dunlap Cc: Karsten Keil Cc: Jonathan Corbet Link: https://lore.kernel.org/r/20230209071400.31476-9-rdunlap@infradead.org Signed-off-by: Jakub Kicinski

isdn: capi: dead code removal

2019-12-11T08:12:38+00:00

The staging isdn drivers are gone, and CONFIG_BT_CMTP is now the only user. This means a lot of the code in the subsystem has no remaining callers and can be removed. Change the capi user space front-end to be part of kernelcapi, and the combined module to only be compiled if BT_CMTP is also enabled, then remove the interfaces that have no remaining callers. As the notifier list and the capi_drivers list have no callers outside of kcapi.c, the implementation gets much simpler. Some definitions from the include/linux/*.h headers are only needed internally and are moved to kcapi.h. Acked-by: David Miller Signed-off-by: Arnd Bergmann Link: https://lore.kernel.org/r/20191210210455.3475361-2-arnd@arndb.de Signed-off-by: Greg Kroah-Hartman

docs: isdn: convert to ReST and add to kAPI bookset

2019-07-31T19:30:25+00:00

The ISDN documentation is a mix of admin guide, uAPI and kAPI. Ideally, it should be split. Yet, not sure if it would worth the troble. Anyway, we have the same kind of mix on several drivers specific documentation. So, just like the others, keep the directory at the root Documentation/ tree, just adding a pointer to it at the kAPI section, as the documentation was written with the Kernel developers in mind. Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Jonathan Corbet