Hi Ulrich,
On Fri, Feb 3, 2017 at 11:38 AM, Ulrich Hecht
<ulrich.hecht+renesas@xxxxxxxxx> wrote:
> Allows tuning of the RX FIFO fill threshold and timeout. (The latter is
> only applicable to SCIFA and SCIFB).
>
> Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@xxxxxxxxx>
> Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> ---
> drivers/tty/serial/sh-sci.c | 87 +++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 87 insertions(+)
>
> diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
> index 4a165ed..f95a56c 100644
> --- a/drivers/tty/serial/sh-sci.c
> +++ b/drivers/tty/serial/sh-sci.c
> @@ -1055,6 +1055,66 @@ static void rx_fifo_timer_fn(unsigned long arg)
> scif_set_rtrg(port, 1);
> }
>
> +static ssize_t rx_trigger_show(struct device *dev,
> + struct device_attribute *attr,
> + char *buf)
> +{
> + struct uart_port *port = dev_get_drvdata(dev);
> + struct sci_port *sci = to_sci_port(port);
> +
> + return sprintf(buf, "%d\n", sci->rx_trigger);
> +}
> +
> +static ssize_t rx_trigger_store(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf,
> + size_t count)
> +{
> + struct uart_port *port = dev_get_drvdata(dev);
> + struct sci_port *sci = to_sci_port(port);
> + long r;
> +
> + if (kstrtol(buf, 0, &r) == -EINVAL)
> + return -EINVAL;
> + sci->rx_trigger = scif_set_rtrg(port, r);
> + scif_set_rtrg(port, 1);
I seem to have missed the above function call during my earlier review.
What's the purpose of resetting the trigger immediately to 1?
This means I can change the value of scif->rx_trigger on the fly, but the
actual value programmed in the hardware is always 1?
I.e. "echo 1 > /sys/class/tty/ttySC0/device/rx_fifo_trigger" fixes serial
console input on e.g. armadillo, but echoing 32 into rx_fifo_trigger doesn't
break it again.
> + return count;
> +}
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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