Hello list, I have an interesting problem, which is described here: https://www.spinics.net/lists/linux-serial/msg22566.html I experienced the same problem on BeagleBone Black platform (armv7 A8: am335x silicon), and the overlay is shown here: https://github.com/ZoranStojsavljevic/MikroE_BeagleBone-Black_BSP-Integration/blob/master/BBB-debian_buster/Master_Example_i2c2_sc16is740.md And the overlay written for /dev/ttySC0 is given here: https://github.com/ZoranStojsavljevic/MikroE_BeagleBone-Black_BSP-Integration/blob/master/BBB-debian_buster/overlay_examples/i2c2_sc16is740/BB-I2C2-SC16IS740-00A0.dts In order to solve this problem, I disabled the following option in kernel .config: ## CONFIG_SERIAL_DEV_CTRL_TTYPORT is not set But I am unsure why keeping enabled generic serial tty bus, and disabling the generic serial tty device driver enables /dev/ttySC0 on the target BBB platform. https://github.com/ZoranStojsavljevic/MikroE_BeagleBone-Black_BSP-Integration/blob/master/BBB-debian_buster/overlay_examples/KERNEL.md Just disabling CONFIG_SERIAL_DEV_CTRL_TTYPORT gives a working /dev/ttySC0 : │ Symbol: SERIAL_DEV_CTRL_TTYPORT [=n] │ Type : bool │ Prompt: Serial device TTY port controller │ Location: │ -> Device Drivers │ -> Character devices │ (1) -> Serial device bus (SERIAL_DEV_BUS [=y]) │ Defined at drivers/tty/serdev/Kconfig:14 │ Depends on: TTY [=y] && SERIAL_DEV_BUS [=y]=y Again, appears that the generic serial tty bus is enabled, but the solution of the problem is to disable generic tty driver (not sure why)! I hope somebody already encounter this problem from this list. Thank you in advance, Zoran Stojsavljevic
