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@xxxxxxxxxxx>
---
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@xxxxxxxxxxx/
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@xxxxxxxxxxx/
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
+ if (to_sci_port(port)->chan_tx &&
+ !dma_submit_error(to_sci_port(port)->cookie_tx)) {
+ dmaengine_terminate_async(to_sci_port(port)->chan_tx);
+ to_sci_port(port)->cookie_tx = -EINVAL;
+ }
+#endif
}
static void sci_start_rx(struct uart_port *port)
--
2.25.1
