Re: [PATCH v2] serial: sh-sci: Stop dmaengine transfer in sci_stop_tx()
From: Jiri Slaby <jirislaby@kernel.org>
Date: 2021-06-04 10:22:04
Also in:
linux-renesas-soc
On 04. 06. 21, 11:57, Yoshihiro Shimoda wrote:
quoted hunk ↗ jump to hunk
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: - sci_dma_stop_tx() is a macro in the .h file because struct sci_port is declared in the .c file and #ifdef should be in the .h file. - This patch uses dmaengine_terminate_async() so that we can apply this 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 v1: - Don't put #ifdef in the .c file. - Update the commit description. https://lore.kernel.org/linux-renesas-soc/TY2PR01MB3692C545672195370487FA60D83C9@TY2PR01MB3692.jpnprd01.prod.outlook.com/T/#t (local) drivers/tty/serial/sh-sci.c | 2 ++ drivers/tty/serial/sh-sci.h | 16 ++++++++++++++++ 2 files changed, 18 insertions(+)diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index 4baf1316ea72..3793cf9f352c 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c@@ -610,6 +610,8 @@ static void sci_stop_tx(struct uart_port *port) ctrl &= ~SCSCR_TIE; serial_port_out(port, SCSCR, ctrl); + + sci_dma_stop_tx(port); } static void sci_start_rx(struct uart_port *port)diff --git a/drivers/tty/serial/sh-sci.h b/drivers/tty/serial/sh-sci.h index c0dfe4382898..435c674af1ce 100644 --- a/drivers/tty/serial/sh-sci.h +++ b/drivers/tty/serial/sh-sci.h@@ -174,3 +174,19 @@ enum { (((port)->type == PORT_SCI) ? SCI_TDxE_CLEAR : SCIF_TDxE_CLEAR) #define SCxSR_BREAK_CLEAR(port) \ (((port)->type == PORT_SCI) ? SCI_BREAK_CLEAR : SCIF_BREAK_CLEAR) + +#ifdef CONFIG_SERIAL_SH_SCI_DMA +#define sci_dma_stop_tx(port) \
Ouch. First, why this needs to be in a header? Second, please don't do this by a macro.
+{ \
+ struct sci_port *s = to_sci_port(port); \
+ \
+ if (s->chan_tx && !dma_submit_error(s->cookie_tx)) { \
+ dmaengine_terminate_async(s->chan_tx); \
+ s->cookie_tx = -EINVAL; \
+ } \
+}
+#else
+static inline void sci_dma_stop_tx(struct uart_port *port)
+{
+}
+#endif /* CONFIG_SERIAL_SH_SCI_DMA */-- js suse labs