Hello Mathieu,
Am Thu, Aug 08, 2024 at 08:06:37AM +0200 schrieb Mathieu Othacehe:
> 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
I've seen this warning already, when migrating a sam9x60 based board
from LTS kernel 6.1 to 6.6, so thanks for taking care of this.
I can confirm after applying the patch on top of 6.6.44 the warning is
gone, and RS-485 communication still works on our platform, so …
Tested-by: Alexander Dahl <ada@xxxxxxxxxxx>
Does this deserve a Fixes tag for the change which introduced struct
serial_rs485 to the atmel serial driver? Then it should be this:
Fixes: af47c491e3c7 ("serial: atmel: Fill in rs485_supported")
Greets
Alex
> which is contradictory with what's really happening.
>
> Signed-off-by: Mathieu Othacehe <othacehe@xxxxxxx>
> ---
> drivers/tty/serial/atmel_serial.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
> index 0a90964d6d107..09b246c9e389e 100644
> --- a/drivers/tty/serial/atmel_serial.c
> +++ b/drivers/tty/serial/atmel_serial.c
> @@ -2514,7 +2514,7 @@ 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,
> };
> --
> 2.45.2
>
>
