Following the process of phasing out Intel 486 CPU support and other old hardware drivers that were dropped in the Linux 7.1 kernel cycle for reducing the kernel maintenance burden, the upcoming Linux 7.2 cycle is continuing the trend of phasing out some of the old hardware support that is very obsolete, likely having no users on the latest upstream kernels, and no one formally maintaining the obsolete drivers.

The latest driver on the chopping block is the Double Talk driver as an ISA speech synthesizer driver. If being ISA-based isn't enough, the hardware already has functionality in another driver and from the Linux Git activity there has been no meaningful work on this driver in many years (or in more than two decades).

Ethan Nelson-Moore explained in arguing for its removal with this commit :

"The dtlk driver supports the RC Systems DoubleTalk PC ISA speech synthesizer card. It has severe coding style issues and has only received tree-wide fixes and drive-by cleanups in the entire Git history (since Linux 2.6.12-rc2). The same hardware is supported by drivers/accessibility/speakup for screen reader use, but that implementation does not share any code with this driver. Given all of these factors, it is likely the driver is entirely unused. Remove it to reduce future maintenance workload."

Surprisingly, RC Systems still maintains a legacy page for their old DoubleTalk hardware.

The RC Systems DoubleTalk PC ISA speech synthesizer card is woefully outdated and now with the removal in char-misc-next, should be retired in Linux 7.2.