Hi Heikki,
Thank you for your reply.
(2014/03/14 23:16), Heikki Krogerus wrote:
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;
Oh, I'll fix it.
}
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?
Ah, we don't need to set up->fcr = 0 in the previous flow when we
implement as follows:
unsigned char fcr = up->fcr;
... <snip> ...
/*
* If fcr exists, a user has opened this port, changed RX
* trigger, or read RX trigger before. If so, we do not change
* fcr.
*/
if (!fcr)
fcr = uart_config[port_type].fcr;
if ((baud < 2400 && !up->dma) || fifo_bug) {
fcr &= ~UART_FCR_TRIGGER_MASK;
fcr |= UART_FCR_TRIGGER_1;
}
up->fcr = fcr;
<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?
In these implementation, the driver sets up->fcr as
uart_config[up->port.type].fcr first and changes only RX trigger. So,
we don't need to set the bit in a direct way.
Thank you,
Yoshihiro YUNOMAE
--
Yoshihiro YUNOMAE
Software Platform Research Dept. Linux Technology Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: yoshihiro.yunomae...@hitachi.com
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