summaryrefslogtreecommitdiff
path: root/drivers/net/wireless/rt2x00/rt2x00usb.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/net/wireless/rt2x00/rt2x00usb.c')
-rw-r--r--drivers/net/wireless/rt2x00/rt2x00usb.c28
1 files changed, 24 insertions, 4 deletions
diff --git a/drivers/net/wireless/rt2x00/rt2x00usb.c b/drivers/net/wireless/rt2x00/rt2x00usb.c
index 1f5675dd329f..568d73847dca 100644
--- a/drivers/net/wireless/rt2x00/rt2x00usb.c
+++ b/drivers/net/wireless/rt2x00/rt2x00usb.c
@@ -221,7 +221,9 @@ static void rt2x00usb_interrupt_rxdone(struct urb *urb)
struct data_ring *ring = entry->ring;
struct rt2x00_dev *rt2x00dev = ring->rt2x00dev;
struct sk_buff *skb;
+ struct ieee80211_hdr *hdr;
struct rxdata_entry_desc desc;
+ int header_size;
int frame_size;
if (!test_bit(DEVICE_ENABLED_RADIO, &rt2x00dev->flags) ||
@@ -243,19 +245,37 @@ static void rt2x00usb_interrupt_rxdone(struct urb *urb)
* Allocate a new sk buffer to replace the current one.
* If allocation fails, we should drop the current frame
* so we can recycle the existing sk buffer for the new frame.
+ * As alignment we use 2 and not NET_IP_ALIGN because we need
+ * to be sure we have 2 bytes room in the head. (NET_IP_ALIGN
+ * can be 0 on some hardware). We use these 2 bytes for frame
+ * alignment later, we assume that the chance that
+ * header_size % 4 == 2 is bigger then header_size % 2 == 0
+ * and thus optimize alignment by reserving the 2 bytes in
+ * advance.
*/
frame_size = entry->ring->data_size + entry->ring->desc_size;
- skb = dev_alloc_skb(frame_size + NET_IP_ALIGN);
+ skb = dev_alloc_skb(frame_size + 2);
if (!skb)
goto skip_entry;
- skb_reserve(skb, NET_IP_ALIGN);
+ skb_reserve(skb, 2);
skb_put(skb, frame_size);
/*
- * Trim the skb_buffer to only contain the valid
- * frame data (so ignore the device's descriptor).
+ * The data behind the ieee80211 header must be
+ * aligned on a 4 byte boundary.
+ * After that trim the entire buffer down to only
+ * contain the valid frame data excluding the device
+ * descriptor.
*/
+ hdr = (struct ieee80211_hdr *)entry->skb->data;
+ header_size =
+ ieee80211_get_hdrlen(le16_to_cpu(hdr->frame_control));
+
+ if (header_size % 4 == 0) {
+ skb_push(entry->skb, 2);
+ memmove(entry->skb->data, entry->skb->data + 2, skb->len - 2);
+ }
skb_trim(entry->skb, desc.size);
/*