rt2x00: check for dma mappings errors

Check output of dma_map_single functions which nowadays can fail (when
IOMMU is used). On write_beacon callbacks just print error, similar
like padding error is handled by rt2800_write_beacon.

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

4 files changed, 36 insertions, 13 deletions

diff --git a/drivers/net/wireless/rt2x00/rt2400pci.c b/drivers/net/wireless/rt2x00/rt2400pci.c
index a2d2bc2c7b3d..221beaaa83f1 100644
--- a/drivers/net/wireless/rt2x00/rt2400pci.c
+++ b/drivers/net/wireless/rt2x00/rt2400pci.c
@@ -1185,8 +1185,14 @@ static void rt2400pci_write_beacon(struct queue_entry *entry,
         rt2x00_set_field32(&reg, CSR14_BEACON_GEN, 0);
         rt2x00pci_register_write(rt2x00dev, CSR14, reg);
 
-        rt2x00queue_map_txskb(entry);
-
+        if (rt2x00queue_map_txskb(entry)) {
+                ERROR(rt2x00dev, "Fail to map beacon, aborting\n");
+                goto out;
+        }
+        /*
+         * Enable beaconing again.
+         */
+        rt2x00_set_field32(&reg, CSR14_BEACON_GEN, 1);
         /*
          * Write the TX descriptor for the beacon.
          */
@@ -1196,7 +1202,7 @@ static void rt2400pci_write_beacon(struct queue_entry *entry,
          * Dump beacon to userspace through debugfs.
          */
         rt2x00debug_dump_frame(rt2x00dev, DUMP_FRAME_BEACON, entry->skb);
-
+out:
         /*
          * Enable beaconing again.
          */
diff --git a/drivers/net/wireless/rt2x00/rt2500pci.c b/drivers/net/wireless/rt2x00/rt2500pci.c
index 9bea10f53f0a..39edc59e8d03 100644
--- a/drivers/net/wireless/rt2x00/rt2500pci.c
+++ b/drivers/net/wireless/rt2x00/rt2500pci.c
@@ -1338,7 +1338,10 @@ static void rt2500pci_write_beacon(struct queue_entry *entry,
         rt2x00_set_field32(&reg, CSR14_BEACON_GEN, 0);
         rt2x00pci_register_write(rt2x00dev, CSR14, reg);
 
-        rt2x00queue_map_txskb(entry);
+        if (rt2x00queue_map_txskb(entry)) {
+                ERROR(rt2x00dev, "Fail to map beacon, aborting\n");
+                goto out;
+        }
 
         /*
          * Write the TX descriptor for the beacon.
@@ -1349,7 +1352,7 @@ static void rt2500pci_write_beacon(struct queue_entry *entry,
          * Dump beacon to userspace through debugfs.
          */
         rt2x00debug_dump_frame(rt2x00dev, DUMP_FRAME_BEACON, entry->skb);
-
+out:
         /*
          * Enable beaconing again.
          */
diff --git a/drivers/net/wireless/rt2x00/rt2x00.h b/drivers/net/wireless/rt2x00/rt2x00.h
index 9a3f31a543ce..086abb403a4f 100644
--- a/drivers/net/wireless/rt2x00/rt2x00.h
+++ b/drivers/net/wireless/rt2x00/rt2x00.h
@@ -1169,8 +1169,10 @@ static inline bool rt2x00_is_soc(struct rt2x00_dev *rt2x00dev)
 /**
  * rt2x00queue_map_txskb - Map a skb into DMA for TX purposes.
  * @entry: Pointer to &struct queue_entry
+ *
+ * Returns -ENOMEM if mapping fail, 0 otherwise.
  */
-void rt2x00queue_map_txskb(struct queue_entry *entry);
+int rt2x00queue_map_txskb(struct queue_entry *entry);
 
 /**
  * rt2x00queue_unmap_skb - Unmap a skb from DMA.
diff --git a/drivers/net/wireless/rt2x00/rt2x00queue.c b/drivers/net/wireless/rt2x00/rt2x00queue.c
index f35d85a71bbc..e26ec9d817cf 100644
--- a/drivers/net/wireless/rt2x00/rt2x00queue.c
+++ b/drivers/net/wireless/rt2x00/rt2x00queue.c
@@ -87,24 +87,35 @@ struct sk_buff *rt2x00queue_alloc_rxskb(struct queue_entry *entry, gfp_t gfp)
         skbdesc->entry = entry;
 
         if (test_bit(REQUIRE_DMA, &rt2x00dev->cap_flags)) {
-                skbdesc->skb_dma = dma_map_single(rt2x00dev->dev,
-                                                  skb->data,
-                                                  skb->len,
-                                                  DMA_FROM_DEVICE);
+                dma_addr_t skb_dma;
+
+                skb_dma = dma_map_single(rt2x00dev->dev, skb->data, skb->len,
+                                         DMA_FROM_DEVICE);
+                if (unlikely(dma_mapping_error(rt2x00dev->dev, skb_dma))) {
+                        dev_kfree_skb_any(skb);
+                        return NULL;
+                }
+
+                skbdesc->skb_dma = skb_dma;
                 skbdesc->flags |= SKBDESC_DMA_MAPPED_RX;
         }
 
         return skb;
 }
 
-void rt2x00queue_map_txskb(struct queue_entry *entry)
+int rt2x00queue_map_txskb(struct queue_entry *entry)
 {
         struct device *dev = entry->queue->rt2x00dev->dev;
         struct skb_frame_desc *skbdesc = get_skb_frame_desc(entry->skb);
 
         skbdesc->skb_dma =
             dma_map_single(dev, entry->skb->data, entry->skb->len, DMA_TO_DEVICE);
+
+        if (unlikely(dma_mapping_error(dev, skbdesc->skb_dma)))
+                return -ENOMEM;
+
         skbdesc->flags |= SKBDESC_DMA_MAPPED_TX;
+        return 0;
 }
 EXPORT_SYMBOL_GPL(rt2x00queue_map_txskb);
 
@@ -545,8 +556,9 @@ static int rt2x00queue_write_tx_data(struct queue_entry *entry,
         /*
          * Map the skb to DMA.
          */
-        if (test_bit(REQUIRE_DMA, &rt2x00dev->cap_flags))
-                rt2x00queue_map_txskb(entry);
+        if (test_bit(REQUIRE_DMA, &rt2x00dev->cap_flags) &&
+            rt2x00queue_map_txskb(entry))
+                return -ENOMEM;
 
         return 0;
 }