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
/* Clear TIE (Transmit Interrupt Enable) bit in SCSCR */
ctrl = serial_port_in(port, SCSCR);
@@ -610,6 +613,13 @@ static void sci_stop_tx(struct uart_port *port)
ctrl &= ~SCSCR_TIE;
serial_port_out(port, SCSCR, ctrl);
+
+#ifdef CONFIG_SERIAL_SH_SCI_DMA
+ if (s->chan_tx && !dma_submit_error(s->cookie_tx)) {
+ dmaengine_terminate_async(s->chan_tx);
+ s->cookie_tx = -EINVAL;
+ }
+#endif
}
static void sci_start_rx(struct uart_port *port)
--
2.25.1
