From 9f1661718c7fcf82e25c6aed20b729ee372d9d65 Mon Sep 17 00:00:00 2001 From: Ivo van Doorn Date: Sun, 26 Apr 2009 16:08:50 +0200 Subject: rt2x00: Add support for L2 padding during TX/RX Some hardware require L2 padding between header and payload because both must be aligned to a 4-byte boundary. This hardware also is easier during the RX path since we no longer need to move the entire payload but rather only the header to remove the padding (mac80211 only wants the payload to be 4-byte aligned). Signed-off-by: Ivo van Doorn Signed-off-by: John W. Linville --- drivers/net/wireless/rt2x00/rt2x00queue.c | 39 +++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) (limited to 'drivers/net/wireless/rt2x00/rt2x00queue.c') diff --git a/drivers/net/wireless/rt2x00/rt2x00queue.c b/drivers/net/wireless/rt2x00/rt2x00queue.c index 6f78915b364c..bc1742c1d51c 100644 --- a/drivers/net/wireless/rt2x00/rt2x00queue.c +++ b/drivers/net/wireless/rt2x00/rt2x00queue.c @@ -148,6 +148,35 @@ void rt2x00queue_free_skb(struct rt2x00_dev *rt2x00dev, struct sk_buff *skb) dev_kfree_skb_any(skb); } +void rt2x00queue_payload_align(struct sk_buff *skb, + bool l2pad, unsigned int header_length) +{ + struct skb_frame_desc *skbdesc = get_skb_frame_desc(skb); + unsigned int frame_length = skb->len; + unsigned int align = ALIGN_SIZE(skb, header_length); + + if (!align) + return; + + if (l2pad) { + if (skbdesc->flags & SKBDESC_L2_PADDED) { + /* Remove L2 padding */ + memmove(skb->data + align, skb->data, header_length); + skb_pull(skb, align); + skbdesc->flags &= ~SKBDESC_L2_PADDED; + } else { + /* Add L2 padding */ + skb_push(skb, align); + memmove(skb->data, skb->data + align, header_length); + skbdesc->flags |= SKBDESC_L2_PADDED; + } + } else { + /* Generic payload alignment to 4-byte boundary */ + skb_push(skb, align); + memmove(skb->data, skb->data + align, frame_length); + } +} + static void rt2x00queue_create_tx_descriptor_seq(struct queue_entry *entry, struct txentry_desc *txdesc) { @@ -258,6 +287,12 @@ static void rt2x00queue_create_tx_descriptor(struct queue_entry *entry, txdesc->cw_max = entry->queue->cw_max; txdesc->aifs = entry->queue->aifs; + /* + * Header and alignment information. + */ + txdesc->header_length = ieee80211_get_hdrlen_from_skb(entry->skb); + txdesc->l2pad = ALIGN_SIZE(entry->skb, txdesc->header_length); + /* * Check whether this frame is to be acked. */ @@ -416,6 +451,10 @@ int rt2x00queue_write_tx_frame(struct data_queue *queue, struct sk_buff *skb) rt2x00crypto_tx_remove_iv(skb, &txdesc); } + if (test_bit(DRIVER_REQUIRE_L2PAD, &queue->rt2x00dev->flags)) + rt2x00queue_payload_align(entry->skb, true, + txdesc.header_length); + /* * It could be possible that the queue was corrupted and this * call failed. Since we always return NETDEV_TX_OK to mac80211, -- cgit v1.2.1