It is possible that DMA transfer is already complete but, completion
handler is yet to be called, when dmaengine_pause() is called in case of
error condition(like break/rx timeout). This leads to dmaengine_pause()
API to return EINVAL (as descriptor is already NULL) causing
rx_dma_broken flag to be set and effectively disabling RX DMA.
Fix this by calling dmaengine_pause() only when transfer is in progress.
Signed-off-by: Vignesh R <vigneshr@xxxxxx>
---
drivers/tty/serial/8250/8250_omap.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c
index 61ad6c3b20a0..4ad1934ef6ed 100644
--- a/drivers/tty/serial/8250/8250_omap.c
+++ b/drivers/tty/serial/8250/8250_omap.c
@@ -790,6 +790,7 @@ static void omap_8250_rx_dma_flush(struct uart_8250_port *p)
{
struct omap8250_priv *priv = p->port.private_data;
struct uart_8250_dma *dma = p->dma;
+ struct dma_tx_state state;
unsigned long flags;
int ret;
@@ -800,10 +801,12 @@ static void omap_8250_rx_dma_flush(struct uart_8250_port *p)
return;
}
- ret = dmaengine_pause(dma->rxchan);
- if (WARN_ON_ONCE(ret))
- priv->rx_dma_broken = true;
-
+ ret = dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state);
+ if (ret == DMA_IN_PROGRESS) {
+ ret = dmaengine_pause(dma->rxchan);
+ if (WARN_ON_ONCE(ret))
+ priv->rx_dma_broken = true;
+ }
spin_unlock_irqrestore(&priv->rx_dma_lock, flags);
__dma_rx_do_complete(p);
--
2.11.0
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