[PATCH v2 4/7] serial: imx: set_termios(): preserve RTS state
From: Sergey Organov <hidden>
Date: 2019-06-26 14:15:10
Also in:
linux-serial
Subsystem:
the rest, tty layer and serial drivers · Maintainers:
Linus Torvalds, Greg Kroah-Hartman, Jiri Slaby
imx_set_termios() cleared RTS on every call, now fixed. Reviewed-by: Sascha Hauer <s.hauer@pengutronix.de> Tested-by: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Sergey Organov <redacted> --- drivers/tty/serial/imx.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-)
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 17e2322..e0f5365 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c@@ -1563,7 +1563,14 @@ imx_uart_set_termios(struct uart_port *port, struct ktermios *termios, spin_lock_irqsave(&sport->port.lock, flags); - ucr2 = UCR2_SRST | UCR2_IRTS; + /* + * Read current UCR2 and save it for future use, then clear all the bits + * except those we will or may need to preserve. + */ + old_ucr2 = imx_uart_readl(sport, UCR2); + ucr2 = old_ucr2 & (UCR2_TXEN | UCR2_RXEN | UCR2_ATEN | UCR2_CTS); + + ucr2 |= UCR2_SRST | UCR2_IRTS; if ((termios->c_cflag & CSIZE) == CS8) ucr2 |= UCR2_WS;
@@ -1632,7 +1639,6 @@ imx_uart_set_termios(struct uart_port *port, struct ktermios *termios, imx_uart_writel(sport, old_ucr1 & ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN), UCR1); - old_ucr2 = imx_uart_readl(sport, UCR2); imx_uart_writel(sport, old_ucr2 & ~UCR2_ATEN, UCR2); while (!(imx_uart_readl(sport, USR2) & USR2_TXDC))
@@ -1640,7 +1646,6 @@ imx_uart_set_termios(struct uart_port *port, struct ktermios *termios, /* then, disable everything */ imx_uart_writel(sport, old_ucr2 & ~(UCR2_TXEN | UCR2_RXEN | UCR2_ATEN), UCR2); - old_ucr2 &= (UCR2_TXEN | UCR2_RXEN | UCR2_ATEN); /* custom-baudrate handling */ div = sport->port.uartclk / (baud * 16);
@@ -1678,8 +1683,7 @@ imx_uart_set_termios(struct uart_port *port, struct ktermios *termios, imx_uart_writel(sport, old_ucr1, UCR1); - /* set the parity, stop bits and data size */ - imx_uart_writel(sport, ucr2 | old_ucr2, UCR2); + imx_uart_writel(sport, ucr2, UCR2); if (UART_ENABLE_MS(&sport->port, termios->c_cflag)) imx_uart_enable_ms(&sport->port);
--
2.10.0.1.g57b01a3
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