Re: [PATCH v3] serial: sh-sci: Stop dmaengine transfer in sci_stop_tx()

[Greg KH <gregkh@linuxfoundation.org>]

On Wed, Jun 09, 2021 at 10:49:02AM +0900, Yoshihiro Shimoda wrote:
> Stop dmaengine transfer in sci_stop_tx(). Otherwise, the following
> message is possible output when system enters suspend and while
> transferring data, because clearing TIE bit in SCSCR is not able to
> stop any dmaengine transfer.
> 
>     sh-sci e6550000.serial: ttySC1: Unable to drain transmitter
> 
> Note that this patch uses dmaengine_terminate_async() so that
> we can apply this patch into longterm kernel v4.9.x or later.
> 
> Fixes: 73a19e4c0301 ("serial: sh-sci: Add DMA support.")
> Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> ---
>  Changes from v2:
>  - Don't use a macro.
>  - Revise the commit descrption.
>  https://lore.kernel.org/linux-renesas-soc/20210604095704.756190-1-yoshihiro.shimoda.uh@renesas.com/
> 
>  Changes from v1:
>  - Don't put #ifdef in the .c file.
>  - Update the commit description.
>  https://lore.kernel.org/linux-renesas-soc/20210602114108.510527-1-yoshihiro.shimoda.uh@renesas.com/
> 
>  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 4baf1316ea72..2d5487bf6855 100644
> --- a/drivers/tty/serial/sh-sci.c
> +++ b/drivers/tty/serial/sh-sci.c
> @@ -610,6 +610,14 @@ static void sci_stop_tx(struct uart_port *port)
>  	ctrl &= ~SCSCR_TIE;
>  
>  	serial_port_out(port, SCSCR, ctrl);
> +
> +#ifdef CONFIG_SERIAL_SH_SCI_DMA

Please no #ifdef in .c files.

thanks,

greg k-h