As noted back in March, the plan with Linux 6.4 is to start removing old, unused and unmaintained PCMCIA drivers . As part of that process to begin dropping old PCMCIA/CardBus driver code from the kernel, all of the PCMCIA "char" drivers were on the chopping block. Linus Torvalds pulled in the char/misc changes this week for Linux 6.4 and indeed those drivers are now removed. Meanwhile this pull introduced the new AMD CDX subsystem.

Greg Kroah-Hartman nominated the char PCMCIA drivers for removal as they are "buggy and receive only minimal care" along with the fact that other kernel developers are also in favor of removing most of the PCMCIA drivers completely.

The Omnikey Cardman 4000 driver, Omnikey Cardman 4040 driver, SCR24X Chip Card Interface driver, and SyncLink PC Card support are the drivers affected by this initial char removal in Linux 6.4. Separately via the USB subsystem is also removing PCMCIA/CardBus to USB drivers .

Expect more PCMCIA code to be removing over coming kernel cycles for drivers deemed broken or without any users remaining. Thanks to clearing out the old PCMCIA char code, the char/misc pull request for the Linux 6.4 merge window about breaks even at 11,014 insertions and 10982 deletions.

With the char pull request there are various driver updates and also the introduction of the AMD CDX subsystem. Learn more about AMD CDX within AMD CDX Bus Landing For Linux 6.4 To Interface Between APUs & FPGAs .