Messages in this thread | | | Date | Tue, 11 Jun 2019 15:44:15 +0300 | From | Andy Shevchenko <> | Subject | Re: [PATCH 2/2 v5] tty/serial/8250: use mctrl_gpio helpers |
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On Tue, Jun 11, 2019 at 12:56:03PM +0200, Stefan Roese wrote: > From: Yegor Yefremov <yegorslists@googlemail.com> > > This patch permits the usage for GPIOs to control > the CTS/RTS/DTR/DSR/DCD/RI signals.
> static inline void serial8250_out_MCR(struct uart_8250_port *up, int value) > { > serial_out(up, UART_MCR, value); > + > + if (up->gpios) { > + int mctrl_gpio = 0; > + > + if (value & UART_MCR_RTS) > + mctrl_gpio |= TIOCM_RTS; > + if (value & UART_MCR_DTR) > + mctrl_gpio |= TIOCM_DTR; > + > + mctrl_gpio_set(up->gpios, mctrl_gpio); > + } > } > > static inline int serial8250_in_MCR(struct uart_8250_port *up) > { > - return serial_in(up, UART_MCR); > + int mctrl; > + > + mctrl = serial_in(up, UART_MCR); > + > + if (up->gpios) { > + int mctrl_gpio = 0; > + > + /* save current MCR values */ > + if (mctrl & UART_MCR_RTS) > + mctrl_gpio |= TIOCM_RTS; > + if (mctrl & UART_MCR_DTR) > + mctrl_gpio |= TIOCM_DTR; > + > + mctrl_gpio = mctrl_gpio_get_outputs(up->gpios, &mctrl_gpio); > + if (mctrl_gpio & TIOCM_RTS) > + mctrl |= UART_MCR_RTS; > + else > + mctrl &= ~UART_MCR_RTS; > + > + if (mctrl_gpio & TIOCM_DTR) > + mctrl |= UART_MCR_DTR; > + else > + mctrl &= ~UART_MCR_DTR; > + } > + > + return mctrl; > }
These are using OR logic with potentially volatile data. Shouldn't we mask unused bits in UART_MCR in case of up->gpios != NULL?
> + if (up->gpios == 0)
This is type inconsistency with this check as far as I understand. I guess you have to do either (up->gpios == NULL), or (!up->gpios).
> ret = 0;
+ Blank line.
> + if (up->gpios) > + return mctrl_gpio_get(up->gpios, &ret);
-- With Best Regards, Andy Shevchenko
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