With Linux 7.1 ISDN, ham radio, and other old network code was removed in lightening the kernel source tree by around 138 thousand lines of code. Some additional Linux networking code cleaning is expected for Linux 7.2 with the ISA and PCMCIA hardware around ARCnet set to be removed.

For those still using ARCnet for that pre-Ethernet networking technology from decades ago, Linux kernel developers plan to end support for ARCnet with ISA and PCMCIA adapters. Linux developers acknowledge ARCnet is still used in some embedded / industrial / building automation environments and thus are not ripping out the ARCnet code in full. Rather, just removing the ISA and PCMCIA adapter support for Attached Resource Computer Network as they are likely not used in any environments running a modern, upstream Linux kernel.

Ethan Nelson-Moore explained in the patch dropping ARCnet PCMCIA and ISA support:

"While ARCnet is still used in industrial environments, and cards are still manufactured, it is unlikely anyone is still using it with ISA and PCMCIA cards. Reduce future maintenance burden by removing all ISA and PCMCIA ARCnet drivers and documentation related to them. Update instructions for loading modules and passing parameters to work on modern kernels and with the com20020_pci driver. Also take the opportunity to document the rest of the module parameters, correct a file path in Documentation/networking/arcnet.rst, and change a reference to /etc/rc.inet1, which no longer exists, to refer to ifconfig."

With the removal of that 5.2k lines of ISA and PCMCIA specific code now in net-next, the action should take place for the upcoming Linux 7.2 kernel cycle. This follows other PCMCIA drivers recently removed from the Linux kernel too in acknowledging anyone left still using PCMCIA adapters is likely not running a modern upstream Linux kernel, if they are there is always the Linux LTS releases.