Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 6a171b29 authored by Jason Uy's avatar Jason Uy Committed by Greg Kroah-Hartman
Browse files

serial: 8250_dw: Allow hardware flow control to be used 



In the most common use case, the Synopsys DW UART driver does not
set the set_termios callback function.  This prevents UPSTAT_AUTOCTS
from being set when the UART flag CRTSCTS is set.  As a result, the
driver will use software flow control as opposed to hardware flow
control.

To fix the problem, the set_termios callback function is set to the
DW specific function.  The logic to set UPSTAT_AUTOCTS is moved so
that any clock error will not affect setting the hardware flow
control.

Reviewed-by: default avatarScott Branden <scott.branden@broadcom.com>
Reviewed-by: default avatarRay Jui <ray.jui@broadcom.com>
Signed-off-by: default avatarJason Uy <jason.uy@broadcom.com>
Reviewed-by: default avatarKefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent dfc80387

drivers/tty/serial/8250/8250_dw.c

+2 −3
Original line number Diff line number Diff line
@@ -248,11 +248,11 @@ static void dw8250_set_termios(struct uart_port *p, struct ktermios *termios, 
	if (!ret)

		p->uartclk = rate;



out:

	p->status &= ~UPSTAT_AUTOCTS;

	if (termios->c_cflag & CRTSCTS)

		p->status |= UPSTAT_AUTOCTS;



out:

	serial8250_do_set_termios(p, termios, old);

}
@@ -326,13 +326,11 @@ static void dw8250_quirks(struct uart_port *p, struct dw8250_data *data) 
			p->serial_in = dw8250_serial_in32;

			data->uart_16550_compatible = true;

		}

		p->set_termios = dw8250_set_termios;

	}



	/* Platforms with iDMA */

	if (platform_get_resource_byname(to_platform_device(p->dev),

					 IORESOURCE_MEM, "lpss_priv")) {

		p->set_termios = dw8250_set_termios;

		data->dma.rx_param = p->dev->parent;

		data->dma.tx_param = p->dev->parent;

		data->dma.fn = dw8250_idma_filter;
@@ -414,6 +412,7 @@ static int dw8250_probe(struct platform_device *pdev) 
	p->serial_in	= dw8250_serial_in;

	p->serial_out	= dw8250_serial_out;

	p->set_ldisc	= dw8250_set_ldisc;

	p->set_termios	= dw8250_set_termios;



	p->membase = devm_ioremap(dev, regs->start, resource_size(regs));

	if (!p->membase)