Hi Greg,

From: Greg KH, Sent: Wednesday, June 9, 2021 9:38 PM

On Wed, Jun 09, 2021 at 10:49:02AM +0900, Yoshihiro Shimoda wrote:

quoted

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>

 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.

I got it. I'll fix this somehow...

Best regards,
Yoshihiro Shimoda