On Thu, May 07, 2020 at 02:53:36PM +0100, Sean Young wrote: > serio drivers can only send one byte at a time. If the underlying tty > is a usb serial port, then each byte will be put into separate usb > urbs, which is not efficient. > > Additionally, the Infrared Toy device refuses to transmit IR if the > IR data is sent one byte at a time. IR data is formatted in u16 values, > and the firmware expects complete u16 values in the packet. > > https://github.com/DangerousPrototypes/USB_IR_Toy/blob/master/Firmware-main/IRs.c#L240 Ummm, serial protocol data size is at most 9 bits so I have no earthly idea how they expect to get 16. serio is explicitly byte-oriented layer, of you need to exchange larger data I'd recommend using USB natively maybe? Thanks. -- Dmitry