[06/12] wl1251: fix payload alignment

Commit Message

Kalle Valo Nov. 26, 2009, 3:09 p.m. UTC

None

Patch

diff --git a/drivers/net/wireless/wl12xx/wl1251_rx.c b/drivers/net/wireless/wl12xx/wl1251_rx.c
index f84cc89..04f3dcd 100644
--- a/drivers/net/wireless/wl12xx/wl1251_rx.c
+++ b/drivers/net/wireless/wl12xx/wl1251_rx.c
@@ -22,6 +22,7 @@ 
  *
  */
 
+#include <linux/string.h>
 #include <linux/skbuff.h>
 #include <net/mac80211.h>
 
@@ -32,6 +33,9 @@ 
 #include "wl1251_cmd.h"
 #include "wl1251_acx.h"
 
+/* needs to be divisible by four because of DMA */
+#define WL1251_RX_ALIGNMENT	4
+
 static void wl1251_rx_header(struct wl1251 *wl,
 			     struct wl1251_rx_descriptor *desc)
 {
@@ -106,6 +110,7 @@  static void wl1251_rx_body(struct wl1251 *wl,
 	struct sk_buff *skb;
 	struct ieee80211_rx_status status;
 	u8 *rx_buffer, beacon = 0;
+	unsigned char *from, *to;
 	u16 length, *fc;
 	u32 curr_id, last_id_inc, rx_packet_ring_addr;
 
@@ -126,12 +131,15 @@  static void wl1251_rx_body(struct wl1251 *wl,
 	if (wl->rx_current_buffer)
 		rx_packet_ring_addr += wl->data_path->rx_packet_ring_chunk_size;
 
-	skb = dev_alloc_skb(length);
+	skb = dev_alloc_skb(length + WL1251_RX_ALIGNMENT);
 	if (!skb) {
 		wl1251_error("Couldn't allocate RX frame");
 		return;
 	}
 
+	/* for the case if payload is unaligned */
+	skb_reserve(skb, WL1251_RX_ALIGNMENT);
+
 	rx_buffer = skb_put(skb, length);
 	wl1251_mem_read(wl, rx_packet_ring_addr, rx_buffer, length);
 
@@ -140,6 +148,13 @@  static void wl1251_rx_body(struct wl1251 *wl,
 
 	fc = (u16 *)skb->data;
 
+	if (ieee80211_hdrlen(*fc) & 0x3) {
+		from = skb->data;
+		to = skb_push(skb, 2);
+		memmove(to, from, skb->len);
+		fc = (u16 *) skb->data;
+	}
+
 	if ((*fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_BEACON)
 		beacon = 1;