Messages in this thread | | | Subject | Re: [PATCH 3/3 v6] tty/serial/8250: use mctrl_gpio helpers | From | Stefan Roese <> | Date | Mon, 17 Jun 2019 14:42:00 +0200 |
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On 17.06.19 11:51, Yegor Yefremov wrote:
<snip>
>>> @@ -1944,11 +1948,15 @@ unsigned int serial8250_do_get_mctrl(struct uart_port *port) >>> { >>> struct uart_8250_port *up = up_to_u8250p(port); >>> unsigned int status; >>> + unsigned int val = 0; >>> >>> serial8250_rpm_get(up); >>> status = serial8250_modem_status(up); >>> serial8250_rpm_put(up); >>> >>> + if (up->gpios) >>> + return mctrl_gpio_get(up->gpios, &val); >>> + >> >> What happens when you have a mixed setup i.e. CTS controlled by UART >> but other status pins controlled by GPIO? In this case CTS status >> won't be returned. Do I see it right?
Yes, your analysis does seem to be correct. Please note that I did not intentionally did change it this way. I was not thinking about such a "mixed design".
> What about something like this: > > unsigned int serial8250_do_get_mctrl(struct uart_port *port) > { > struct uart_8250_port *up = up_to_u8250p(port); > unsigned int status; > unsigned int val; > > serial8250_rpm_get(up); > status = serial8250_modem_status(up); > serial8250_rpm_put(up); > > val = serial8250_MSR_to_TIOCM(status); > if (up->gpios) > mctrl_gpio_get(up->gpios, &val); > > return val; > }
Looks good to me, thanks. Do you have such a setup with some modem control signal handled via GPIO and some via the UART? Could you test such a change?
Thanks, Stefan
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