Hi Greg,
> From: Greg KH, Sent: Wednesday, June 2, 2021 8:57 PM
>
> On Wed, Jun 02, 2021 at 08:41:08PM +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
> >
> > Notes 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@xxxxxxxxxxx>
> > ---
> > drivers/tty/serial/sh-sci.c | 10 ++++++++++
> > 1 file changed, 10 insertions(+)
> >
> > diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
> > index 4baf1316ea72..e7130be48946 100644
> > --- a/drivers/tty/serial/sh-sci.c
> > +++ b/drivers/tty/serial/sh-sci.c
> > @@ -600,6 +600,9 @@ static void sci_start_tx(struct uart_port *port)
> > static void sci_stop_tx(struct uart_port *port)
> > {
> > unsigned short ctrl;
> > +#ifdef CONFIG_SERIAL_SH_SCI_DMA
> > + struct sci_port *s = to_sci_port(port);
> > +#endif
>
> Please do not put #ifdef in .c files, this should be possible without
> that.
This #ifdef could avoid a compile warning if CONFIG_SERIAL_SH_SCI_DMA was not defined:
drivers/tty/serial/sh-sci.c: In function 'sci_stop_tx':
drivers/tty/serial/sh-sci.c:603:19: warning: unused variable 's' [-Wunused-variable]
struct sci_port *s = to_sci_port(port);
Anyway, I'll avoid to use #ifdef in .c file. Thank you for your review!
Best regards,
Yoshihiro Shimoda
> thanks,
>
> greg k-h
