Re: [PATCH v7 3/3] tty: 8250_omap: Use software emulated RS485 direction control

From: Andy Shevchenko
Date: Sat Jan 23 2016 - 10:20:32 EST


On Tue, Jan 19, 2016 at 10:33 PM, Matwey V. Kornilov <matwey@xxxxxxxxxx> wrote:
> Use software emulated RS485 direction control to provide RS485 API existed in
> omap_serial driver. Note that 8250_omap issues interrupt on shift register
> empty which is single prerequesite for using software emulated RS485.


> +static int omap_8250_rs485_config(struct uart_port *port, struct serial_rs485 *rs485)
> +{
> + struct uart_8250_port *up = up_to_u8250p(port);
> +
> + /* Clamp the delays to [0, 100ms] */

It's not exactly clamping but rather cutting extra as I can see below.

> + rs485->delay_rts_before_send = min(rs485->delay_rts_before_send, 100U);
> + rs485->delay_rts_after_send = min(rs485->delay_rts_after_send, 100U);

> + /* Both serial8250_em485_* functions are idempotent */

Better to decode what functions do you mean here.

> + if (rs485->flags & SER_RS485_ENABLED) {
> + int ret = serial8250_em485_init(up);
> + if (ret) {
> + rs485->flags &= ~SER_RS485_ENABLED;
> + port->rs485.flags &= ~SER_RS485_ENABLED;
> + }

> + return ret;
> + } else

You have to do } else { in multi-line branches, but luckily there is
redundant else keyword.

And checkpatch.pl doesn't tell you anything?

> + serial8250_em485_destroy(up);
> +
> + return 0;
> +}

--
With Best Regards,
Andy Shevchenko