On Tue, 2016-12-06 at 14:34 -0800, Jason Uy wrote: > 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. > It should not affect Intel HW since we are using clock for it (see drivers/mfd/intel-lpss-pci.c, drivers/acpi/acpi_lpss.c). Thus, I'm okay with the change. > Reviewed-by: Scott Branden <scott.branden@xxxxxxxxxxxx> > Reviewed-by: Ray Jui <ray.jui@xxxxxxxxxxxx> > Signed-off-by: Jason Uy <jason.uy@xxxxxxxxxxxx> > --- > drivers/tty/serial/8250/8250_dw.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/drivers/tty/serial/8250/8250_dw.c > b/drivers/tty/serial/8250/8250_dw.c > index 459d726..18f1f8b 100644 > --- a/drivers/tty/serial/8250/8250_dw.c > +++ b/drivers/tty/serial/8250/8250_dw.c > @@ -246,11 +246,11 @@ 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); > } > > @@ -308,13 +308,11 @@ 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; > @@ -392,6 +390,7 @@ static int dw8250_probe(struct platform_device > *pdev) > p->iotype = UPIO_MEM; > p->serial_in = dw8250_serial_in; > p->serial_out = dw8250_serial_out; > + p->set_termios = dw8250_set_termios; > > p->membase = devm_ioremap(dev, regs->start, > resource_size(regs)); > if (!p->membase) -- Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> Intel Finland Oy -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html