Hi,
On Fri, Mar 14, 2014 at 11:21:54AM +0900, Yoshihiro YUNOMAE wrote:
> void serial8250_clear_and_reinit_fifos(struct uart_8250_port *p)
> {
> - unsigned char fcr;
> -
> serial8250_clear_fifos(p);
> - fcr = uart_config[p->port.type].fcr;
> - serial_out(p, UART_FCR, fcr);
> + p->fcr = uart_config[p->port.type].fcr;
> + serial_out(p, UART_FCR, p->fcr);
You should allow also the probe drivers to set this..
if (!p->fcr)
p->fcr = uart_config[p->port.type].fcr;
> }
> EXPORT_SYMBOL_GPL(serial8250_clear_and_reinit_fifos);
>
> @@ -2325,10 +2323,19 @@ serial8250_do_set_termios(struct uart_port *port,
> struct ktermios *termios,
> if ((baud < 2400 && !up->dma) || fifo_bug) {
> fcr &= ~UART_FCR_TRIGGER_MASK;
> fcr |= UART_FCR_TRIGGER_1;
> + /* Don't use user setting RX trigger */
> + up->fcr = 0;
I don't know about this but..
> }
> }
>
> /*
> + * If up->fcr exists, a user has opened this port, changed RX trigger,
> + * or read RX trigger before. So, we don't need to change up->fcr here.
> + */
> + if (!up->fcr)
> + up->fcr = fcr;
Why not just set fcr = up->fcr in the beginning of the function?
<snip>
> +static int do_set_rx_int_trig(struct tty_port *port, unsigned char val)
> +{
> + struct uart_state *state = container_of(port, struct uart_state, port);
> + struct uart_port *uport = state->uart_port;
> + struct uart_8250_port *up =
> + container_of(uport, struct uart_8250_port, port);
> + unsigned char fcr;
> + int rx_trig;
> +
> + if (!(up->capabilities & UART_CAP_FIFO) || uport->fifosize <= 1)
> + return -EINVAL;
> +
> + rx_trig = convert_val2rxtrig(up, val);
> + if (rx_trig < 0)
> + return rx_trig;
> +
> + serial8250_clear_fifos(up);
> + if (!up->fcr)
> + /* termios is not set yet */
> + fcr = uart_config[up->port.type].fcr;
> + else
> + fcr = up->fcr;
> + fcr &= ~UART_FCR_TRIGGER_MASK;
> + fcr |= (unsigned char)rx_trig;
> + up->fcr = fcr;
> + serial_out(up, UART_FCR, up->fcr);
> + return 0;
> +}
Where are you setting UART_FCR_ENABLE_FIFO bit? Am I missing
something?
> diff --git a/include/linux/serial_8250.h b/include/linux/serial_8250.h
> index af47a8a..2ce1152 100644
> --- a/include/linux/serial_8250.h
> +++ b/include/linux/serial_8250.h
> @@ -76,6 +76,7 @@ struct uart_8250_port {
> unsigned short bugs; /* port bugs */
> unsigned int tx_loadsz; /* transmit fifo load size */
> unsigned char acr;
> + unsigned char fcr;
I do like to see fcr being added here, but because of a different
reason. I want to be able to set it from the probe drivers.
Br,
--
heikki
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