From: Geert Uytterhoeven geert+renesas@glider.be
[ Upstream commit 775b7ffd7d6d5db320d99b0a485c51e04dfcf9f1 ]
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 Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/tty/serial/sh-sci.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index 66c8bbea06c4..dc0b36ab999a 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -1571,11 +1571,18 @@ 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)