From 596a9171472ba31edce566e938524dbbe3c54183 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ilpo=20J=C3=A4rvinen?= Date: Mon, 6 Jun 2022 13:04:20 +0300 Subject: [PATCH] serial: Clear rs485 struct when non-RS485 mode is set MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit When SER_RS485_ENABLED is not set, having any other flag/field set in serial_rs485 struct does not have an effect different from not having them set. Thus, make the serial_rs485 struct also match the behavior for all flags, not just SER_RS485_ENABLED. Some drivers do similar clearing of rs485 struct in their rs485_config() already, but not all. This change makes the behavior consistent across drivers. Don't try to validate rs485 struct further when no RS485 is requested, this silences some bogus warnings. This change has (minor) userspace visible impact. Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20220606100433.13793-24-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/serial_core.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index f0d7b3d207312..6be5387205648 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -1280,6 +1280,11 @@ static void uart_sanitize_serial_rs485(struct uart_port *port, struct serial_rs4 { u32 supported_flags = port->rs485_supported->flags; + if (!(rs485->flags & SER_RS485_ENABLED)) { + memset(rs485, 0, sizeof(*rs485)); + return; + } + /* pick sane settings if the user hasn't */ if ((supported_flags & (SER_RS485_RTS_ON_SEND|SER_RS485_RTS_AFTER_SEND)) && !(rs485->flags & SER_RS485_RTS_ON_SEND) == @@ -1329,10 +1334,15 @@ static void uart_sanitize_serial_rs485(struct uart_port *port, struct serial_rs4 int uart_rs485_config(struct uart_port *port) { struct serial_rs485 *rs485 = &port->rs485; + int ret; uart_sanitize_serial_rs485(port, rs485); - return port->rs485_config(port, rs485); + ret = port->rs485_config(port, rs485); + if (ret) + memset(rs485, 0, sizeof(*rs485)); + + return ret; } EXPORT_SYMBOL_GPL(uart_rs485_config); -- 2.30.2