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>

diff --git a/drivers/net/irda/sa1100_ir.c b/drivers/net/irda/sa1100_ir.c
index 751f2a9f283b2d9ea4fb41c86fdfcc0af752f89c..84fecce078f6c5b75fe33fb60b6eae502ebd0e3e 100644 (file)
--- 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);