ath9k-htc:respect usb buffer cacheline alignment in reg out path

In ath9k-htc register out path, ath9k-htc will pass skb->data into
usb hcd and usb hcd will do dma mapping and unmapping to the buffer
pointed by skb->data, so we should pass a cache-line aligned address.

This patch replace __dev_alloc_skb with alloc_skb to make skb->data
pointed to a cacheline aligned address simply since ath9k-htc does not
skb_push on the skb and pass it to mac80211, also use kfree_skb to free
the skb allocated by alloc_skb(we can use kfree_skb safely in hardirq
context since skb->destructor is NULL always in the path).

Signed-off-by: Sujith <Sujith.Manoharan@atheros.com>
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/drivers/net/wireless/ath/ath9k/wmi.c b/drivers/net/wireless/ath/ath9k/wmi.c
index acb66544a2aa..f2ff18cf3e60 100644
--- a/drivers/net/wireless/ath/ath9k/wmi.c
+++ b/drivers/net/wireless/ath/ath9k/wmi.c
@@ -213,7 +213,7 @@ free_skb:
 static void ath9k_wmi_ctrl_tx(void *priv, struct sk_buff *skb,
                               enum htc_endpoint_id epid, bool txok)
 {
-        dev_kfree_skb_any(skb);
+        kfree_skb(skb);
 }
 
 int ath9k_wmi_connect(struct htc_target *htc, struct wmi *wmi,
@@ -269,7 +269,7 @@ int ath9k_wmi_cmd(struct wmi *wmi, enum wmi_cmd_id cmd_id,
         if (!wmi)
                 return -EINVAL;
 
-        skb = dev_alloc_skb(headroom + cmd_len);
+        skb = alloc_skb(headroom + cmd_len, GFP_ATOMIC);
         if (!skb)
                 return -ENOMEM;
 
@@ -313,7 +313,7 @@ out:
         ath_print(common, ATH_DBG_WMI,
                   "WMI failure for: %s\n", wmi_cmd_to_name(cmd_id));
         mutex_unlock(&wmi->op_mutex);
-        dev_kfree_skb_any(skb);
+        kfree_skb(skb);
 
         return ret;
 }