1 files changed, 13 insertions, 1 deletions

diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c
index 0340ee6ba970..826c5c4a2103 100644
--- a/drivers/tty/serial/8250/8250_omap.c
+++ b/drivers/tty/serial/8250/8250_omap.c
@@ -112,6 +112,7 @@ struct omap8250_priv {
         struct work_struct qos_work;
         struct uart_8250_dma omap8250_dma;
         spinlock_t rx_dma_lock;
+        bool rx_dma_broken;
 };
 
 static u32 uart_read(struct uart_8250_port *up, u32 reg)
@@ -761,6 +762,7 @@ 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;
         unsigned long           flags;
+        int ret;
 
         spin_lock_irqsave(&priv->rx_dma_lock, flags);
 
@@ -769,7 +771,9 @@ static void omap_8250_rx_dma_flush(struct uart_8250_port *p)
                 return;
         }
 
-        dmaengine_pause(dma->rxchan);
+        ret = dmaengine_pause(dma->rxchan);
+        if (WARN_ON_ONCE(ret))
+                priv->rx_dma_broken = true;
 
         spin_unlock_irqrestore(&priv->rx_dma_lock, flags);
 
@@ -813,6 +817,9 @@ static int omap_8250_rx_dma(struct uart_8250_port *p, unsigned int iir)
                 break;
         }
 
+        if (priv->rx_dma_broken)
+                return -EINVAL;
+
         spin_lock_irqsave(&priv->rx_dma_lock, flags);
 
         if (dma->rx_running)
@@ -1207,6 +1214,11 @@ static int omap8250_probe(struct platform_device *pdev)
 
                         if (of_machine_is_compatible("ti,am33xx"))
                                 priv->habit |= OMAP_DMA_TX_KICK;
+                        /*
+                         * pause is currently not supported atleast on omap-sdma
+                         * and edma on most earlier kernels.
+                         */
+                        priv->rx_dma_broken = true;
                 }
         }
 #endif