ok then, lets do it in the driver...
Author: Bruno Randolf <bruno@xxxxxxxxxxxxx>
Date: Mon Oct 15 19:46:59 2007 +0900
handle padding between header and data
Atheros hardware requires the header to be padded to 4 byte (32 bit)
boundaries. It expects the payload data to start at multiples of 4 byte for TX
frames and will add the padding for received frames. For most headers there is
no need for padding, since they are multiples of 4 already - except QoS and 4
address headers.
Changes-licensed-under: 3-clause-BSD
Signed-off-by: Bruno Randolf <bruno@xxxxxxxxxxxxx>
diff --git a/drivers/net/wireless/ath5k/base.c
b/drivers/net/wireless/ath5k/base.c
index 0997577..0a7cb41 100644
--- a/drivers/net/wireless/ath5k/base.c
+++ b/drivers/net/wireless/ath5k/base.c
@@ -375,6 +375,8 @@ static void ath_tasklet_rx(unsigned long data)
u16 len;
u8 stat;
int ret;
+ int hdrlen;
+ int pad;
spin_lock(&sc->rxbuflock);
do {
@@ -449,13 +451,20 @@ accept:
PCI_DMA_FROMDEVICE);
bf->skb = NULL;
- if (unlikely((ieee80211_get_hdrlen_from_skb(skb) & 3) &&
- net_ratelimit()))
- printk(KERN_DEBUG "rx len is not %%4: %u\n",
- ieee80211_get_hdrlen_from_skb(skb));
-
skb_put(skb, len);
+ /*
+ * the hardware adds a padding to 4 byte boundaries between
+ * the header and the payload data if the header length is
+ * not multiples of 4 - remove it
+ */
+ hdrlen = ieee80211_get_hdrlen_from_skb(skb);
+ if (hdrlen & 3) {
+ pad = hdrlen % 4;
+ memmove(skb->data + pad, skb->data, hdrlen);
+ skb_pull(skb, pad);
+ }
+
if (sc->opmode == IEEE80211_IF_TYPE_MNTR)
rxs.mactime = ath_extend_tsf(sc->ah,
ds->ds_rxstat.rs_tstamp);
@@ -1153,7 +1162,7 @@ static int ath_tx_bf(struct ath_softc *sc, struct
ath_buf *bf,
struct ath_txq *txq = sc->txq;
struct ath_desc *ds = bf->desc;
struct sk_buff *skb = bf->skb;
- unsigned int hdrpad, pktlen, flags, keyidx = AR5K_TXKEYIX_INVALID;
+ unsigned int pktlen, flags, keyidx = AR5K_TXKEYIX_INVALID;
int ret;
flags = AR5K_TXDESC_INTREQ | AR5K_TXDESC_CLRDMASK;
@@ -1165,12 +1174,7 @@ static int ath_tx_bf(struct ath_softc *sc, struct
ath_buf *bf,
if (ctl->flags & IEEE80211_TXCTL_NO_ACK)
flags |= AR5K_TXDESC_NOACK;
- if ((ieee80211_get_hdrlen_from_skb(skb) & 3) && net_ratelimit())
- printk(KERN_DEBUG "tx len is not %%4: %u\n",
- ieee80211_get_hdrlen_from_skb(skb));
-
- hdrpad = 0;
- pktlen = skb->len - hdrpad + FCS_LEN;
+ pktlen = skb->len + FCS_LEN;
if (!(ctl->flags & IEEE80211_TXCTL_DO_NOT_ENCRYPT)) {
keyidx = ctl->key_idx;
@@ -1214,12 +1218,32 @@ static int ath_tx(struct ieee80211_hw *hw, struct
sk_buff *skb,
struct ath_softc *sc = hw->priv;
struct ath_buf *bf;
unsigned long flags;
+ int hdrlen;
+ int pad;
ath_dump_skb(skb, "t");
if (sc->opmode == IEEE80211_IF_TYPE_MNTR)
DPRINTF(sc, ATH_DEBUG_XMIT, "tx in monitor (scan?)\n");
+ /*
+ * the hardware expects the header padded to 4 byte boundaries
+ * if this is not the case we add the padding after the header
+ */
+ hdrlen = ieee80211_get_hdrlen_from_skb(skb);
+ if (hdrlen & 3) {
+ pad = hdrlen % 4;
+ if (skb_headroom(skb) < pad) {
+ if (net_ratelimit())
+ printk(KERN_ERR "ath: tx hdrlen not %%4: %d "
+ "not enough headroom to pad %d\n",
+ hdrlen, pad);
+ return -1;
+ }
+ skb_push(skb, pad);
+ memmove(skb->data, skb->data+pad, hdrlen);
+ }
+
sc->led_txrate = ctl->tx_rate;
spin_lock_irqsave(&sc->txbuflock, flags);
-
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