From 4b2aad92ef4ca1f6921bcfc76860ddeadcc02e7b Mon Sep 17 00:00:00 2001 From: Heiko Stuebner Date: Fri, 1 Jun 2018 14:40:16 +0200 Subject: [PATCH 4/7] serial: 8250: Start rs485 after registering port if rs485 is enabled in probe Before registering a port 8250 drivers may read devicetree information regarding rs485 emulation, but starting the em485 emulation at that point would only keep the em485 structure in the template uart port. Also at that point before the port is registered possible gpios for rts/dtr are not acquired yet as well. So simply check after acquiring the port if the rs485-enable flag is set and start the config callback in that case. Signed-off-by: Heiko Stuebner --- drivers/tty/serial/8250/8250_core.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c index e682390ce0de..beab1c22b34d 100644 --- a/drivers/tty/serial/8250/8250_core.c +++ b/drivers/tty/serial/8250/8250_core.c @@ -1068,6 +1068,15 @@ int serial8250_register_8250_port(struct uart_8250_port *up) if (up->dl_write) uart->dl_write = up->dl_write; + if (uart->port.rs485_config && + (uart->port.rs485.flags & SER_RS485_ENABLED)) { + dev_dbg(uart->port.dev, "starting in rs485 mode\n"); + ret = uart->port.rs485_config(&uart->port, + &uart->port.rs485); + if (ret < 0) + goto out_unlock; + } + if (uart->port.type != PORT_8250_CIR) { if (serial8250_isa_config != NULL) serial8250_isa_config(0, &uart->port, -- 2.24.1