diff mbox

[RFC,05/14] drivers: wireless: ar5523: use container_of

Message ID 1425318028-26531-6-git-send-email-fw@strlen.de
State RFC, archived
Delegated to: David Miller
Headers show

Commit Message

Florian Westphal March 2, 2015, 5:40 p.m. UTC
Compile tested only due to lack of hw.

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.

Cc: linux-wireless@vger.kernel.org
Signed-off-by: Florian Westphal <fw@strlen.de>
---
 drivers/net/wireless/ath/ar5523/ar5523.c | 8 ++++----
 drivers/net/wireless/ath/ar5523/ar5523.h | 1 -
 2 files changed, 4 insertions(+), 5 deletions(-)

Comments

Pontus Fuchs March 3, 2015, 9:16 a.m. UTC | #1
On 2015-03-02 18:40, Florian Westphal wrote:
> Compile tested only due to lack of hw.
>
> 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.
>
> Cc: linux-wireless@vger.kernel.org
> Signed-off-by: Florian Westphal <fw@strlen.de>

Tested-by: Pontus Fuchs <pontus.fuchs@gmail.com>

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diff mbox

Patch

diff --git a/drivers/net/wireless/ath/ar5523/ar5523.c b/drivers/net/wireless/ath/ar5523/ar5523.c
index f920506..7410ac0 100644
--- a/drivers/net/wireless/ath/ar5523/ar5523.c
+++ b/drivers/net/wireless/ath/ar5523/ar5523.c
@@ -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 +815,12 @@  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");
diff --git a/drivers/net/wireless/ath/ar5523/ar5523.h b/drivers/net/wireless/ath/ar5523/ar5523.h
index 00c6fd3..9a322a6 100644
--- a/drivers/net/wireless/ath/ar5523/ar5523.h
+++ b/drivers/net/wireless/ath/ar5523/ar5523.h
@@ -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;
 };