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: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
Reviewed-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
Tested-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
Signed-off-by: Sergey Organov <sorganov@xxxxxxxxx>
---
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 32f36d8..059ba35 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -974,10 +974,22 @@ 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
