[PATCH] serial: omap_8250: Fix RTS handling, part B

From: Peter Hurley
Date: Wed Dec 31 2014 - 16:33:21 EST


Because the OMAP3 UART ignores MCR[1] (RTS) in autoRTS mode, autoRTS
mode must not be enabled unless RTS is set (or port->mctrl & TIOCM_RTS,
which is equivalent).

Fixes premature raising of RTS in omap_8250_set_termios() -- RTS was
raised even before UART mode was selected.
Fixes raise of RTS after port has been shutdown; omap_8250_pm() re-enabled
RTS after omap_8250_shutdown().

Cc: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Signed-off-by: Peter Hurley <peter@xxxxxxxxxxxxxxxxxx>
---
drivers/tty/serial/8250/8250_omap.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c
index 428f384..316c37b 100644
--- a/drivers/tty/serial/8250/8250_omap.c
+++ b/drivers/tty/serial/8250/8250_omap.c
@@ -272,7 +272,10 @@ static void omap8250_restore_regs(struct uart_8250_port *up)
serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
serial_dl_write(up, priv->quot);

- serial_out(up, UART_EFR, priv->efr);
+ if (up->port.mctrl & TIOCM_RTS)
+ serial_out(up, UART_EFR, priv->efr);
+ else
+ serial_out(up, UART_EFR, priv->efr & ~UART_EFR_RTS);

/* Configure flow control */
serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
@@ -468,18 +471,18 @@ static void omap_8250_set_termios(struct uart_port *port,
static void omap_8250_pm(struct uart_port *port, unsigned int state,
unsigned int oldstate)
{
- struct uart_8250_port *up =
- container_of(port, struct uart_8250_port, port);
- struct omap8250_priv *priv = up->port.private_data;
+ struct uart_8250_port *up = up_to_u8250p(port);
+ u8 efr;

pm_runtime_get_sync(port->dev);
serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
- serial_out(up, UART_EFR, priv->efr | UART_EFR_ECB);
+ efr = serial_in(up, UART_EFR);
+ serial_out(up, UART_EFR, efr | UART_EFR_ECB);
serial_out(up, UART_LCR, 0);

serial_out(up, UART_IER, (state != 0) ? UART_IERX_SLEEP : 0);
serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
- serial_out(up, UART_EFR, priv->efr);
+ serial_out(up, UART_EFR, efr);
serial_out(up, UART_LCR, 0);

pm_runtime_mark_last_busy(port->dev);
--
2.2.1

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