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| author | Lino Sanfilippo <l.sanfilippo@kunbus.com> | 2024-01-03 07:18:16 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-01-04 16:29:51 +0100 |
| commit | 74eab89b26ac433ad857292f4707b43c1a8f0209 (patch) | |
| tree | 1b4e588483d56a2dadf9c462b9f153ca799c92c9 /drivers/tty | |
| parent | c73986913fa47e71e0b1ad7f039f6444915e8810 (diff) | |
| download | linux-stable-74eab89b26ac433ad857292f4707b43c1a8f0209.tar.gz linux-stable-74eab89b26ac433ad857292f4707b43c1a8f0209.tar.bz2 linux-stable-74eab89b26ac433ad857292f4707b43c1a8f0209.zip | |
serial: core, imx: do not set RS485 enabled if it is not supported
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>
Suggested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20240103061818.564-6-l.sanfilippo@kunbus.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/serial/imx.c | 7 | ||||
| -rw-r--r-- | drivers/tty/serial/serial_core.c | 3 |
2 files changed, 3 insertions, 7 deletions
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c index 8b7d9c5a7455..4aa72d5aeafb 100644 --- a/drivers/tty/serial/imx.c +++ b/drivers/tty/serial/imx.c @@ -2211,7 +2211,6 @@ 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, @@ -2295,8 +2294,6 @@ 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); @@ -2331,10 +2328,6 @@ static int imx_uart_probe(struct platform_device *pdev) if (ret) goto err_clk; - 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 b9606db78c92..b56ed8c376b2 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -3607,6 +3607,9 @@ 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) { |