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Message-Id: <20231018174840.28977-6-l.sanfilippo@kunbus.com>
Date: Wed, 18 Oct 2023 19:48:38 +0200
From: Lino Sanfilippo <l.sanfilippo@...bus.com>
To: gregkh@...uxfoundation.org, jirislaby@...nel.org,
ilpo.jarvinen@...ux.intel.com
Cc: u.kleine-koenig@...gutronix.de, shawnguo@...nel.org,
s.hauer@...gutronix.de, mcoquelin.stm32@...il.com,
alexandre.torgue@...s.st.com, cniedermaier@...electronics.com,
linux-kernel@...r.kernel.org, linux-serial@...r.kernel.org,
LinoSanfilippo@....de, lukas@...ner.de, p.rosenberger@...bus.com,
Lino Sanfilippo <l.sanfilippo@...bus.com>,
stable@...r.kernel.org
Subject: [PATCH v4 5/7] serial: core, imx: do not set RS485 enabled if it is not supported
If the imx driver cannot support RS485 it sets the ports rs485_supported
structure to NULL. But it still calls uart_get_rs485_mode() which may set
the RS485_ENABLED flag nevertheless.
This may lead to an attempt to configure RS485 even if it is not supported
when the flag is evaluated in uart_configure_port() at port startup.
Avoid this by bailing out of uart_get_rs485_mode() if the RS485_ENABLED
flag is not supported by the caller.
With this fix a check for RTS availability is now obsolete in the imx
driver, since it can not evaluate to true any more. Remove this check, too.
Fixes: 00d7a00e2a6f ("serial: imx: Fill in rs485_supported")
Cc: Shawn Guo <shawnguo@...nel.org>
Cc: Sascha Hauer <s.hauer@...gutronix.de>
Cc: stable@...r.kernel.org
Suggested-by: Uwe Kleine-König <u.kleine-koenig@...gutronix.de>
Signed-off-by: Lino Sanfilippo <l.sanfilippo@...bus.com>
---
drivers/tty/serial/imx.c | 4 ----
drivers/tty/serial/serial_core.c | 3 +++
2 files changed, 3 insertions(+), 4 deletions(-)
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index edb2ec6a5567..c8c19bf8585d 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -2332,10 +2332,6 @@ static int imx_uart_probe(struct platform_device *pdev)
return ret;
}
- if (sport->port.rs485.flags & SER_RS485_ENABLED &&
- (!sport->have_rtscts && !sport->have_rtsgpio))
- dev_err(&pdev->dev, "no RTS control, disabling rs485\n");
-
/*
* If using the i.MX UART RTS/CTS control then the RTS (CTS_B)
* signal cannot be set low during transmission in case the
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 49dd5e864719..c85275a573e3 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -3586,6 +3586,9 @@ int uart_get_rs485_mode(struct uart_port *port)
int ret;
int rx_during_tx_gpio_flag;
+ if (!(port->rs485_supported.flags & SER_RS485_ENABLED))
+ return 0;
+
ret = device_property_read_u32_array(dev, "rs485-rts-delay",
rs485_delay, 2);
if (!ret) {
--
2.40.1
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