Re: [PATCH v2 3/6] serial: Implement flush callback

Simon Glass
2022-08-11T14:49:25Z

On Thu, 11 Aug 2022 at 06:39, Pali Rohár <pali@kernel.org> wrote:
>
> UART drivers have putc/puts functions which just put characters into HW
> transmit queue and do not wait until all data are transmitted.
>
> Implement flush callback via serial driver's pending(false) callback which
> waits until HW transmit all characters from the queue.
>
> Signed-off-by: Pali Rohár <pali@kernel.org>
> ---
> drivers/serial/serial-uclass.c | 22 ++++++++++++++++++++++
> 1 file changed, 22 insertions(+)

Reviewed-by: Simon Glass <sjg@chromium.org>

But let's always add this to the struct.

>
> diff --git a/drivers/serial/serial-uclass.c b/drivers/serial/serial-uclass.c
> index 4b7819fa473b..71ea88e31c9f 100644
> --- a/drivers/serial/serial-uclass.c
> +++ b/drivers/serial/serial-uclass.c
> @@ -238,6 +238,18 @@ static void _serial_puts(struct udevice *dev, const char *str)
> } while (*str);
> }
>
> +#ifdef CONFIG_CONSOLE_FLUSH_SUPPORT
> +static void _serial_flush(struct udevice *dev)
> +{
> + struct dm_serial_ops *ops = serial_get_ops(dev);
> +
> + if (!ops->pending)
> + return;
> + while (ops->pending(dev, false) > 0)
> + ;
> +}
> +#endif
> +
> static int __serial_getc(struct udevice *dev)
> {
> struct dm_serial_ops *ops = serial_get_ops(dev);
> @@ -412,6 +424,13 @@ static void serial_stub_puts(struct stdio_dev *sdev, const char *str)
> _serial_puts(sdev->priv, str);
> }
>
> +#ifdef CONFIG_CONSOLE_FLUSH_SUPPORT
> +static void serial_stub_flush(struct stdio_dev *sdev)
> +{
> + _serial_flush(sdev->priv);
> +}
> +#endif
> +
> static int serial_stub_getc(struct stdio_dev *sdev)
> {
> return _serial_getc(sdev->priv);
> @@ -571,6 +590,9 @@ static int serial_post_probe(struct udevice *dev)
> sdev.priv = dev;
> sdev.putc = serial_stub_putc;
> sdev.puts = serial_stub_puts;
> +#ifdef CONFIG_CONSOLE_FLUSH_SUPPORT
> + sdev.flush = serial_stub_flush;
> +#endif
> sdev.getc = serial_stub_getc;
> sdev.tstc = serial_stub_tstc;
>
> --
> 2.20.1
>