serial: sh-sci: Stop TX DMA workqueue during port shutdown
The transmit DMA workqueue is never stopped, hence the work function may
be called after the port has been shut down.
Fix this race condition by cancelling queued work, if any, before DMA
release. Don't initialize the work if DMA initialization failed, as it
won't be used anyway.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index c5c891c..f3432cc 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -1293,6 +1293,7 @@
{
struct dma_chan *chan = s->chan_tx_saved;
+ cancel_work_sync(&s->work_tx);
s->chan_tx_saved = s->chan_tx = NULL;
s->cookie_tx = -EINVAL;
dmaengine_terminate_all(chan);
@@ -1548,10 +1549,9 @@
__func__, UART_XMIT_SIZE,
port->state->xmit.buf, &s->tx_dma_addr);
+ INIT_WORK(&s->work_tx, work_fn_tx);
s->chan_tx_saved = s->chan_tx = chan;
}
-
- INIT_WORK(&s->work_tx, work_fn_tx);
}
chan = sci_request_dma_chan(port, DMA_DEV_TO_MEM);