The speakup driver that's long existed within the Linux kernel is a speech synthesizer that can interface with various synthesizer hardware and from user-space software can interface with /dev/synth for submitting data to the synthesizer. With Linux 6.9 the speakup driver is seeing two useful improvements.

First, the speakup driver has a fix for 8-bit characters submitted to /dev/synth . Support for unsigned characters is added to avoid a situation where garbled text could occur when writing 8-bit characters to the device.

The other notable addition for Linux 6.9 is adding the /dev/synthu device for the speakup driver. Due to most applications now using UTF-8 encoding, /dev/synthu is a new interface over /dev/synth for allowing synthesizing non-latin1 characters. The new /dev/synthu device is limited to 16-bit Unicode like the rest of speakup with any odd input or beyond 16-bit to be auto-discarded.

Those unfamiliar with this speech synthesis Linux kernel accessibility feature can learn more about it and usage via [1]Linux-Speakup.org .

These speakup improvements were sent in as part of the [2]char/misc changes for the Linux 6.9 merge window. The rest of the char/misc pull is the usual assortment of small and fairly random driver updates/fixes.



[1] http://www.linux-speakup.org/spkguide.txt

[2] https://lore.kernel.org/lkml/Zfwv2y7P7BneKqMZ@kroah.com/