serial: imx: set_mctrl(): correctly restore autoRTS state (197540dc) · Commits · 戴 / test

imx_uart_set_mctrl() happened to set UCR2_CTSC bit whenever TIOCM_RTS was set, no matter if RTS/CTS handshake is enabled or not. Now fixed by turning handshake on only when CRTSCTS bit for the port is set. Reviewed-by:

Sascha Hauer <s.hauer@pengutronix.de> Tested-by:

Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by:

Sergey Organov <sorganov@gmail.com> Link: https://lore.kernel.org/r/1564167161-3972-3-git-send-email-sorganov@gmail.com Signed-off-by:

Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/imx.c

+14 −2

Original line number	Original line	Diff line number	Diff line
	@@ -974,10 +974,22 @@ static void imx_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
	if (!(port->rs485.flags & SER_RS485_ENABLED)) {		if (!(port->rs485.flags & SER_RS485_ENABLED)) {
	u32 ucr2;		u32 ucr2;

			/*
			* Turn off autoRTS if RTS is lowered and restore autoRTS
			* setting if RTS is raised.
			*/
	ucr2 = imx_uart_readl(sport, UCR2);		ucr2 = imx_uart_readl(sport, UCR2);
	ucr2 &= ~(UCR2_CTS \| UCR2_CTSC);		ucr2 &= ~(UCR2_CTS \| UCR2_CTSC);
	if (mctrl & TIOCM_RTS)		if (mctrl & TIOCM_RTS) {
	ucr2 \|= UCR2_CTS \| UCR2_CTSC;		ucr2 \|= UCR2_CTS;
			/*
			* UCR2_IRTS is unset if and only if the port is
			* configured for CRTSCTS, so we use inverted UCR2_IRTS
			* to get the state to restore to.
			*/
			if (!(ucr2 & UCR2_IRTS))
			ucr2 \|= UCR2_CTSC;
			}
	imx_uart_writel(sport, ucr2, UCR2);		imx_uart_writel(sport, ucr2, UCR2);
	}		}

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