diff options
Diffstat (limited to 'drivers/net/wireless/rt2x00/rt2x00usb.c')
| -rw-r--r-- | drivers/net/wireless/rt2x00/rt2x00usb.c | 28 |
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); /* |