NET: sa11x0-ir: handle DMA mapping errors properly

Handle DMA mapping errors in the rx skb allocation and tx paths.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 14 insertions, 2 deletions

diff --git a/drivers/net/irda/sa1100_ir.c b/drivers/net/irda/sa1100_ir.c
index 751f2a9f283..84fecce078f 100644
--- a/drivers/net/irda/sa1100_ir.c
+++ b/drivers/net/irda/sa1100_ir.c
@@ -82,7 +82,6 @@ static int sa1100_irda_rx_alloc(struct sa1100_irda *si)
                 return 0;
 
         si->rxskb = alloc_skb(HPSIR_MAX_RXLEN + 1, GFP_ATOMIC);
-
         if (!si->rxskb) {
                 printk(KERN_ERR "sa1100_ir: out of memory for RX SKB\n");
                 return -ENOMEM;
@@ -97,6 +96,11 @@ static int sa1100_irda_rx_alloc(struct sa1100_irda *si)
         si->rxbuf_dma = dma_map_single(si->dev, si->rxskb->data,
                                         HPSIR_MAX_RXLEN,
                                         DMA_FROM_DEVICE);
+        if (dma_mapping_error(si->dev, si->rxbuf_dma)) {
+                dev_kfree_skb_any(si->rxskb);
+                return -ENOMEM;
+        }
+
         return 0;
 }
 
@@ -518,7 +522,8 @@ static void sa1100_irda_fir_error(struct sa1100_irda *si, struct net_device *dev
                 netif_rx(skb);
         } else {
                 /*
-                 * Remap the buffer.
+                 * Remap the buffer - it was previously mapped, and we
+                 * hope that this succeeds.
                  */
                 si->rxbuf_dma = dma_map_single(si->dev, si->rxskb->data,
                                                 HPSIR_MAX_RXLEN,
@@ -701,6 +706,13 @@ static int sa1100_irda_hard_xmit(struct sk_buff *skb, struct net_device *dev)
                 si->txskb = skb;
                 si->txbuf_dma = dma_map_single(si->dev, skb->data,
                                          skb->len, DMA_TO_DEVICE);
+                if (dma_mapping_error(si->dev, si->txbuf_dma)) {
+                        si->txskb = NULL;
+                        netif_wake_queue(dev);
+                        dev->stats.tx_dropped++;
+                        dev_kfree_skb(skb);
+                        return NETDEV_TX_OK;
+                }
 
                 sa1100_start_dma(si->txdma, si->txbuf_dma, skb->len);