ar5523: use container_of

If we want to shrink skb->cb then we'd have to see about
reducing struct ieee80211_tx_info, which gets embedded inside
skb->cb[].

It provides a scratch space to be used by wireless drivers.
ar5523 uses the maximum space available today (40 bytes), but it seems
we don't need this -- data->skb pointer seems to always point back to the
skb whose cb buffer the data structure resides, iow, given a pointer to the
embedded control buffer we can infer the skb address.

Tested-by: Pontus Fuchs <pontus.fuchs@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
This commit is contained in:
Florian Westphal 2015-03-10 15:25:39 +01:00 committed by Kalle Valo
parent dd29511248
commit 6faf22d9ca
2 changed files with 5 additions and 5 deletions

View File

@ -779,8 +779,6 @@ static void ar5523_tx(struct ieee80211_hw *hw,
ieee80211_stop_queues(hw);
}
data->skb = skb;
spin_lock_irqsave(&ar->tx_data_list_lock, flags);
list_add_tail(&data->list, &ar->tx_queue_pending);
spin_unlock_irqrestore(&ar->tx_data_list_lock, flags);
@ -817,10 +815,13 @@ static void ar5523_tx_work_locked(struct ar5523 *ar)
if (!data)
break;
skb = data->skb;
txi = container_of((void *)data, struct ieee80211_tx_info,
driver_data);
txqid = 0;
txi = IEEE80211_SKB_CB(skb);
skb = container_of((void *)txi, struct sk_buff, cb);
paylen = skb->len;
urb = usb_alloc_urb(0, GFP_KERNEL);
if (!urb) {
ar5523_err(ar, "Failed to allocate TX urb\n");

View File

@ -74,7 +74,6 @@ struct ar5523_tx_cmd {
struct ar5523_tx_data {
struct list_head list;
struct ar5523 *ar;
struct sk_buff *skb;
struct urb *urb;
};