2022-08-03 02:03:05

by Sherry Sun

Subject: [PATCH] tty: serial: lpuart: disable flow control when wait transmit engine complete

When TX fifo has dirty data, user initialize the port and wait transmit
engine complete, it should disable the flow control, otherwise tx fifo
never be empty.

Signed-off-by: Sherry Sun <[email protected]>
---
drivers/tty/serial/fsl_lpuart.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
index fc7d235a1e27..f0fccd2ff7ac 100644
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -2172,6 +2172,7 @@ lpuart32_set_termios(struct uart_port *port, struct ktermios *termios,
uart_update_timeout(port, termios->c_cflag, baud);

/* wait transmit engin complete */
+ lpuart32_write(&sport->port, 0, UARTMODIR);
lpuart32_wait_bit_set(&sport->port, UARTSTAT, UARTSTAT_TC);

/* disable transmit and receive */
--
2.17.1

2022-08-04 07:03:33

by Jiri Slaby

Subject: Re: [PATCH] tty: serial: lpuart: disable flow control when wait transmit engine complete

On 03. 08. 22, 3:55, Sherry Sun wrote:
> When TX fifo has dirty data, user initialize the port and wait transmit
> engine complete, it should disable the flow control, otherwise tx fifo
> never be empty.

Sorry I cannot parse the above. Care to rephrase? (And maybe spellcheck?)

> Signed-off-by: Sherry Sun <[email protected]>
> ---
> drivers/tty/serial/fsl_lpuart.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
> index fc7d235a1e27..f0fccd2ff7ac 100644
> --- a/drivers/tty/serial/fsl_lpuart.c
> +++ b/drivers/tty/serial/fsl_lpuart.c
> @@ -2172,6 +2172,7 @@ lpuart32_set_termios(struct uart_port *port, struct ktermios *termios,
> uart_update_timeout(port, termios->c_cflag, baud);
>
> /* wait transmit engin complete */
> + lpuart32_write(&sport->port, 0, UARTMODIR);
> lpuart32_wait_bit_set(&sport->port, UARTSTAT, UARTSTAT_TC);
>
> /* disable transmit and receive */

thanks,
--
js
suse labs

2022-08-04 07:28:26

by Sherry Sun

Subject: RE: [PATCH] tty: serial: lpuart: disable flow control when wait transmit engine complete

> On 03. 08. 22, 3:55, Sherry Sun wrote:
> > When TX fifo has dirty data, user initialize the port and wait
> > transmit engine complete, it should disable the flow control,
> > otherwise tx fifo never be empty.
>
> Sorry I cannot parse the above. Care to rephrase? (And maybe spellcheck?)

Hi Jiri, sure, maybe some grammatical errors in the commit log, I can send V2 for your check. Thanks!

Best regards
Sherry
>
> > Signed-off-by: Sherry Sun <[email protected]>
> > ---
> > drivers/tty/serial/fsl_lpuart.c | 1 +
> > 1 file changed, 1 insertion(+)
> >
> > diff --git a/drivers/tty/serial/fsl_lpuart.c
> > b/drivers/tty/serial/fsl_lpuart.c index fc7d235a1e27..f0fccd2ff7ac
> > 100644
> > --- a/drivers/tty/serial/fsl_lpuart.c
> > +++ b/drivers/tty/serial/fsl_lpuart.c
> > @@ -2172,6 +2172,7 @@ lpuart32_set_termios(struct uart_port *port,
> struct ktermios *termios,
> > uart_update_timeout(port, termios->c_cflag, baud);
> >
> > /* wait transmit engin complete */
> > + lpuart32_write(&sport->port, 0, UARTMODIR);
> > lpuart32_wait_bit_set(&sport->port, UARTSTAT, UARTSTAT_TC);
> >
> > /* disable transmit and receive */
>
> thanks,
> --
> js
> suse labs