diff options
| author | Vignesh R <vigneshr@ti.com> | 2017-01-20 13:46:52 +0530 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-01-20 14:44:37 +0100 |
| commit | 75f54acc086940ccef8b6d67ba8537529bda104c (patch) | |
| tree | 3078f13318caaa38fb8967e8a43701db1f9070bd | |
| parent | c92d781f1a5ea19708b1e1e2b85a3fbd4a738b30 (diff) | |
serial: 8250_omap: pause DMA only if DMA transfer in progress
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@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/tty/serial/8250/8250_omap.c | 11 |
1 files 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); |