6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mathieu Othacehe <othacehe@xxxxxxx> commit c9f6613b16123989f2c3bd04b1d9b2365d6914e7 upstream. In RS485 mode, the RTS pin is driven high by hardware when the transmitter is operating. This behaviour cannot be changed. This means that the driver should claim that it supports SER_RS485_RTS_ON_SEND and not SER_RS485_RTS_AFTER_SEND. Otherwise, when configuring the port with the SER_RS485_RTS_ON_SEND, one get the following warning: kern.warning kernel: atmel_usart_serial atmel_usart_serial.2.auto: ttyS1 (1): invalid RTS setting, using RTS_AFTER_SEND instead which is contradictory with what's really happening. Signed-off-by: Mathieu Othacehe <othacehe@xxxxxxx> Cc: stable <stable@xxxxxxxxxx> Tested-by: Alexander Dahl <ada@xxxxxxxxxxx> Fixes: af47c491e3c7 ("serial: atmel: Fill in rs485_supported") Link: https://lore.kernel.org/r/20240808060637.19886-1-othacehe@xxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/tty/serial/atmel_serial.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/tty/serial/atmel_serial.c +++ b/drivers/tty/serial/atmel_serial.c @@ -2522,7 +2522,7 @@ static const struct uart_ops atmel_pops }; static const struct serial_rs485 atmel_rs485_supported = { - .flags = SER_RS485_ENABLED | SER_RS485_RTS_AFTER_SEND | SER_RS485_RX_DURING_TX, + .flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | SER_RS485_RX_DURING_TX, .delay_rts_before_send = 1, .delay_rts_after_send = 1, };