what do you think about the following solution?
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.
This adds a new hw flag IEEE80211_HW_HEADER_PADDING to tell mac80211 that such
a padding is needed.
---
drivers/net/wireless/ath5k/base.c | 1 +
include/net/mac80211.h | 8 ++++++++
net/mac80211/rx.c | 20 ++++++++++++++++++++
net/mac80211/tx.c | 5 +++++
4 files changed, 34 insertions(+), 0 deletions(-)
diff --git a/drivers/net/wireless/ath5k/base.c
b/drivers/net/wireless/ath5k/base.c
index 08530d5..b705f68 100644
--- a/drivers/net/wireless/ath5k/base.c
+++ b/drivers/net/wireless/ath5k/base.c
@@ -2382,6 +2382,7 @@ static int __devinit ath_pci_probe(struct pci_dev *pdev,
hw->extra_tx_headroom = 2;
hw->channel_change_time = 5000;
hw->max_rssi = 127; /* FIXME: get a real value for this. */
+ hw->flags |= IEEE80211_HW_HEADER_PADDING;
sc = hw->priv;
sc->hw = hw;
sc->pdev = pdev;
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 2b1bffb..18c30e6 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -662,12 +662,20 @@ enum sta_notify_cmd {
* @IEEE80211_HW_DEFAULT_REG_DOMAIN_CONFIGURED:
* Channels are already configured to the default regulatory domain
* specified in the device's EEPROM
+ *
+ * @IEEE80211_HW_HEADER_PADDING:
+ * Some 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.
*/
enum ieee80211_hw_flags {
IEEE80211_HW_HOST_GEN_BEACON_TEMPLATE = 1<<0,
IEEE80211_HW_RX_INCLUDES_FCS = 1<<1,
IEEE80211_HW_HOST_BROADCAST_PS_BUFFERING = 1<<2,
IEEE80211_HW_DEFAULT_REG_DOMAIN_CONFIGURED = 1<<3,
+ IEEE80211_HW_HEADER_PADDING = 1<<4,
};
/**
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 064924c..2ad94d1 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -419,6 +419,25 @@ ieee80211_rx_h_check(struct ieee80211_txrx_data *rx)
static ieee80211_txrx_result
+ieee80211_rx_h_remove_padding(struct ieee80211_txrx_data *rx)
+{
+ struct ieee80211_hw *hw = local_to_hw(rx->local);
+ int hdrlen;
+ int pad;
+
+ if (!(hw->flags & IEEE80211_HW_HEADER_PADDING))
+ return TXRX_CONTINUE;
+
+ hdrlen = ieee80211_get_hdrlen(rx->fc);
+ if ((pad = hdrlen % 4)) {
+ memmove(rx->skb->data + pad, rx->skb->data, hdrlen);
+ skb_pull(rx->skb, pad);
+ }
+
+ return TXRX_CONTINUE;
+}
+
+static ieee80211_txrx_result
ieee80211_rx_h_decrypt(struct ieee80211_txrx_data *rx)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
@@ -1320,6 +1339,7 @@ ieee80211_rx_handler ieee80211_rx_handlers[] =
ieee80211_rx_h_if_stats,
ieee80211_rx_h_passive_scan,
ieee80211_rx_h_check,
+ ieee80211_rx_h_remove_padding,
ieee80211_rx_h_decrypt,
ieee80211_rx_h_sta_process,
ieee80211_rx_h_defragment,
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 957ec3c..ce4c6ce 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -1334,6 +1334,7 @@ int ieee80211_subif_start_xmit(struct sk_buff *skb,
struct net_device *dev)
{
struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
+ struct ieee80211_hw *hw = local_to_hw(local);
struct ieee80211_tx_packet_data *pkt_data;
struct ieee80211_sub_if_data *sdata;
int ret = 1, head_need;
@@ -1410,6 +1411,10 @@ int ieee80211_subif_start_xmit(struct sk_buff *skb,
sta_info_put(sta);
}
+ if (hw->flags & IEEE80211_HW_HEADER_PADDING) {
+ hdrlen = roundup(hdrlen, 4);
+ }
+
hdr.frame_control = cpu_to_le16(fc);
hdr.duration_id = 0;
hdr.seq_ctrl = 0;
--
1.5.3.4
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