From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergey Organov Subject: [PATCH v3 6/7] serial: imx: set_mctrl(): correctly restore autoRTS state Date: Thu, 4 Jul 2019 16:00:28 +0300 Message-ID: <1562245229-709-7-git-send-email-sorganov@gmail.com> References: <20190614072801.3187-1-s.hauer@pengutronix.de> <1562245229-709-1-git-send-email-sorganov@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1562245229-709-1-git-send-email-sorganov@gmail.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: linux-serial@vger.kernel.org Cc: Greg Kroah-Hartman , Sascha Hauer , Sergey Organov , NXP Linux Team , Pengutronix Kernel Team , =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= , linux-arm-kernel@lists.infradead.org List-Id: linux-serial@vger.kernel.org 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 Tested-by: Sascha Hauer Signed-off-by: Sergey Organov --- drivers/tty/serial/imx.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c index 5532887..582a3fd 100644 --- a/drivers/tty/serial/imx.c +++ b/drivers/tty/serial/imx.c @@ -970,10 +970,22 @@ static void imx_uart_set_mctrl(struct uart_port *port, unsigned int mctrl) if (!(port->rs485.flags & SER_RS485_ENABLED)) { u32 ucr2; + /* + * Turn off autoRTS if RTS is lowered and restore autoRTS + * setting if RTS is raised. + */ ucr2 = imx_uart_readl(sport, UCR2); ucr2 &= ~(UCR2_CTS | UCR2_CTSC); - if (mctrl & TIOCM_RTS) - ucr2 |= UCR2_CTS | UCR2_CTSC; + if (mctrl & TIOCM_RTS) { + 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); } -- 2.10.0.1.g57b01a3