@@ -177,45 +177,38 @@ void rt2x00queue_align_payload(struct sk_buff *skb, unsigned int header_length)
void rt2x00queue_insert_l2pad(struct sk_buff *skb, unsigned int header_length)
{
- unsigned int frame_length = skb->len;
+ unsigned int payload_length = skb->len - header_length;
unsigned int header_align = ALIGN_SIZE(skb, 0);
unsigned int payload_align = ALIGN_SIZE(skb, header_length);
unsigned int l2pad = L2PAD_SIZE(header_length);
- if (header_align == payload_align) {
- /*
- * Both header and payload must be moved the same
- * amount of bytes to align them properly. This means
- * we don't use the L2 padding but just move the entire
- * frame.
- */
- rt2x00queue_align_frame(skb);
- } else if (!payload_align) {
- /*
- * Simple L2 padding, only the header needs to be moved,
- * the payload is already properly aligned.
- */
- skb_push(skb, header_align);
- memmove(skb->data, skb->data + header_align, header_length);
- } else {
- /*
- *
- * Complicated L2 padding, both header and payload need
- * to be moved. By default we only move to the start
- * of the buffer, so our header alignment needs to be
- * increased if there is not enough room for the header
- * to be moved.
- */
- if (payload_align > header_align)
- header_align += 4;
+ /*
+ * Adjust the header alignment if the payload needs to be moved more
+ * than the header.
+ */
+ if (payload_align > header_align)
+ header_align += 4;
+
+ /* There is nothing to do if no alignment is needed */
+ if (!header_align)
+ return;
- skb_push(skb, header_align);
- memmove(skb->data, skb->data + header_align, header_length);
+ /* Reserve the amount of space needed in front of the frame */
+ skb_push(skb, header_align);
+
+ /*
+ * Move the header.
+ */
+ memmove(skb->data, skb->data + header_align, header_length);
+
+ /* Move the payload, if present and if required */
+ if (payload_length && payload_align)
memmove(skb->data + header_length + l2pad,
skb->data + header_length + l2pad + payload_align,
- frame_length - header_length);
- skb_trim(skb, frame_length + l2pad);
- }
+ payload_length);
+
+ /* Trim the skb to the correct size */
+ skb_trim(skb, header_length + l2pad + payload_length);
}
void rt2x00queue_remove_l2pad(struct sk_buff *skb, unsigned int header_length)
@@ -343,7 +336,8 @@ static void rt2x00queue_create_tx_descriptor(struct queue_entry *entry,
* Header and alignment information.
*/
txdesc->header_length = ieee80211_get_hdrlen_from_skb(entry->skb);
- if (test_bit(DRIVER_REQUIRE_L2PAD, &rt2x00dev->flags))
+ if (test_bit(DRIVER_REQUIRE_L2PAD, &rt2x00dev->flags) &&
+ (entry->skb->len > txdesc->header_length))
txdesc->l2pad = L2PAD_SIZE(txdesc->header_length);
/*