@@ -2206,7 +2206,6 @@ static enum hrtimer_restart imx_trigger_stop_tx(struct hrtimer *t)
return HRTIMER_NORESTART;
}
-static const struct serial_rs485 imx_no_rs485 = {}; /* No RS485 if no RTS */
static const struct serial_rs485 imx_rs485_supported = {
.flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | SER_RS485_RTS_AFTER_SEND |
SER_RS485_RX_DURING_TX,
@@ -2290,8 +2289,6 @@ static int imx_uart_probe(struct platform_device *pdev)
/* RTS is required to control the RS485 transmitter */
if (sport->have_rtscts || sport->have_rtsgpio)
sport->port.rs485_supported = imx_rs485_supported;
- else
- sport->port.rs485_supported = imx_no_rs485;
sport->port.flags = UPF_BOOT_AUTOCONF;
timer_setup(&sport->timer, imx_uart_timeout, 0);
@@ -2328,10 +2325,6 @@ 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
@@ -3600,6 +3600,9 @@ int uart_get_rs485_mode(struct uart_port *port)
u32 rs485_delay[2];
int ret;
+ 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) {
If the imx driver cannot support RS485 it nullifies the ports rs485_supported structure. 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. So remove this check. Furthermore the explicit nullifcation of rs485_supported is not needed, since the memory has already been set to zeros at allocation. So remove this, too. Fixes: 00d7a00e2a6f ("serial: imx: Fill in rs485_supported") Cc: Shawn Guo <shawnguo@kernel.org> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: stable@vger.kernel.org Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Suggested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> --- drivers/tty/serial/imx.c | 7 ------- drivers/tty/serial/serial_core.c | 3 +++ 2 files changed, 3 insertions(+), 7 deletions(-)