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| author | Jochen Mades <jochen@mades.net> | 2021-01-23 05:10:14 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-01-26 14:53:12 +0100 |
| commit | 62f676ff7898f6c1bd26ce014564773a3dc00601 (patch) | |
| tree | feb07f387e7f8050c49f3a67e6fa9fcc28cd7e13 /drivers/tty | |
| parent | serial: stm32: fix software flow control transfer (diff) | |
| download | linux-62f676ff7898f6c1bd26ce014564773a3dc00601.tar.xz linux-62f676ff7898f6c1bd26ce014564773a3dc00601.zip | |
serial: pl011: Fix incorrect rs485 RTS polarity on set_mctrl
Commit 8d479237727c ("serial: amba-pl011: add RS485 support") sought to
keep RTS deasserted on set_mctrl if rs485 is enabled. However it did so
only if deasserted RTS polarity is high. Fix it in case it's low.
Fixes: 8d479237727c ("serial: amba-pl011: add RS485 support")
Cc: stable@vger.kernel.org # v5.15+
Cc: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Signed-off-by: Jochen Mades <jochen@mades.net>
[lukas: copyedit commit message, add stable designation]
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Link: https://lore.kernel.org/r/85fa3323ba8c307943969b7343e23f34c3e652ba.1642909284.git.lukas@wunner.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/serial/amba-pl011.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c index 1f1df46242f9..f64c475a1379 100644 --- a/drivers/tty/serial/amba-pl011.c +++ b/drivers/tty/serial/amba-pl011.c @@ -1582,8 +1582,12 @@ static void pl011_set_mctrl(struct uart_port *port, unsigned int mctrl) container_of(port, struct uart_amba_port, port); unsigned int cr; - if (port->rs485.flags & SER_RS485_ENABLED) - mctrl &= ~TIOCM_RTS; + if (port->rs485.flags & SER_RS485_ENABLED) { + if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND) + mctrl &= ~TIOCM_RTS; + else + mctrl |= TIOCM_RTS; + } cr = pl011_read(uap, REG_CR); |