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authorGeert Uytterhoeven <geert+renesas@glider.be>2019-06-24 14:35:40 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-07-03 19:31:30 +0200
commit775b7ffd7d6d5db320d99b0a485c51e04dfcf9f1 (patch)
tree91670d866a6c7e877d97c5a08df774f005b901f1 /drivers/tty/serial/sh-sci.c
parent8493eab02608b0e82f67b892aa72882e510c31d0 (diff)
downloadlinux-775b7ffd7d6d5db320d99b0a485c51e04dfcf9f1.tar.gz
serial: sh-sci: Terminate TX DMA during buffer flushing
While the .flush_buffer() callback clears sci_port.tx_dma_len since
commit 1cf4a7efdc71cab8 ("serial: sh-sci: Fix race condition causing
garbage during shutdown"), it does not terminate a transmit DMA
operation that may be in progress.

Fix this by terminating any pending DMA operations, and resetting the
corresponding cookie.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Tested-by: Eugeniu Rosca <erosca@de.adit-jv.com>

Link: https://lore.kernel.org/r/20190624123540.20629-3-geert+renesas@glider.be
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/serial/sh-sci.c')
-rw-r--r--drivers/tty/serial/sh-sci.c11
1 files changed, 9 insertions, 2 deletions
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index d4504daff992..d18c680aa64b 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -1656,11 +1656,18 @@ static void sci_free_dma(struct uart_port *port)
 
 static void sci_flush_buffer(struct uart_port *port)
 {
+	struct sci_port *s = to_sci_port(port);
+
 	/*
 	 * In uart_flush_buffer(), the xmit circular buffer has just been
-	 * cleared, so we have to reset tx_dma_len accordingly.
+	 * cleared, so we have to reset tx_dma_len accordingly, and stop any
+	 * pending transfers
 	 */
-	to_sci_port(port)->tx_dma_len = 0;
+	s->tx_dma_len = 0;
+	if (s->chan_tx) {
+		dmaengine_terminate_async(s->chan_tx);
+		s->cookie_tx = -EINVAL;
+	}
 }
 #else /* !CONFIG_SERIAL_SH_SCI_DMA */
 static inline void sci_request_dma(struct uart_port *port)