Re: [PATCH 4/7] serial: sh-sci: increase RX FIFO trigger defaults for (H)SCIF

[Geert Uytterhoeven]

Hi Uli,

On Fri, Dec 9, 2016 at 1:36 PM, Ulrich Hecht
 wrote:
> Signed-off-by: Ulrich Hecht 
> ---
>  drivers/tty/serial/sh-sci.c | 8 
>  1 file changed, 8 insertions(+)
>
> diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
> index 844288f..ce3cf03 100644
> --- a/drivers/tty/serial/sh-sci.c
> +++ b/drivers/tty/serial/sh-sci.c

> @@ -2729,6 +2734,7 @@ static int sci_init_single(struct platform_device *dev,
> sci_port->overrun_reg = SCLSR;
> sci_port->overrun_mask = SCLSR_ORER;
> sci_port->sampling_rate_mask = SCI_SR_RANGE(8, 32);
> +   sci_port->rx_trigger = 64;
> break;
> case PORT_SCIFA:
> port->fifosize = 64;
> @@ -2747,12 +2753,14 @@ static int sci_init_single(struct platform_device 
> *dev,
> sci_port->overrun_mask = SCLSR_ORER;
> sci_port->sampling_rate_mask = SCI_SR(32);
> }
> +   sci_port->rx_trigger = 8;

PORT_SCIF is also used with SCIx_SH7705_SCIF_REGTYPE, so this should
be moved inside the "else" branch above.
Then, what to do with the "if" branch?

>From the sh7705/sh7720/sh7721 datasheets, it looks a lot like SCIFA, and thus
would need "sci_port->rx_trigger = 32", and the same handling as SCIFA in
scif_set_rtrg().

See also "[RFC] serial: sh-sci: Correct FIFO stages on sh7705/sh7720/sh7721"
(https://patchwork.kernel.org/patch/6810191/).

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- ge...@linux-m68k.org

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

[PATCH 4/7] serial: sh-sci: increase RX FIFO trigger defaults for (H)SCIF

[Ulrich Hecht]

Signed-off-by: Ulrich Hecht 
---
 drivers/tty/serial/sh-sci.c | 8 
 1 file changed, 8 insertions(+)

diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index 844288f..ce3cf03 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -141,6 +141,7 @@ struct sci_port {
struct timer_list   rx_timer;
unsigned intrx_timeout;
 #endif
+   int rx_trigger;
 
bool autorts;
 };
@@ -2204,6 +2205,7 @@ static void sci_reset(struct uart_port *port)
 {
const struct plat_sci_reg *reg;
unsigned int status;
+   struct sci_port *s = to_sci_port(port);
 
do {
status = serial_port_in(port, SCxSR);
@@ -2223,6 +2225,9 @@ static void sci_reset(struct uart_port *port)
status &= ~(SCLSR_TO | SCLSR_ORER);
serial_port_out(port, SCLSR, status);
}
+
+   if (s->rx_trigger > 1)
+   scif_set_rtrg(port, s->rx_trigger);
 }
 
 static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
@@ -2729,6 +2734,7 @@ static int sci_init_single(struct platform_device *dev,
sci_port->overrun_reg = SCLSR;
sci_port->overrun_mask = SCLSR_ORER;
sci_port->sampling_rate_mask = SCI_SR_RANGE(8, 32);
+   sci_port->rx_trigger = 64;
break;
case PORT_SCIFA:
port->fifosize = 64;
@@ -2747,12 +2753,14 @@ static int sci_init_single(struct platform_device *dev,
sci_port->overrun_mask = SCLSR_ORER;
sci_port->sampling_rate_mask = SCI_SR(32);
}
+   sci_port->rx_trigger = 8;
break;
default:
port->fifosize = 1;
sci_port->overrun_reg = SCxSR;
sci_port->overrun_mask = SCI_ORER;
sci_port->sampling_rate_mask = SCI_SR(32);
+   sci_port->rx_trigger = 1;
break;
}
 
-- 
2.7.4