ath5k: correct packet length in tx descriptors

Packet length calculation (which includes frame check sequence)
should take into account whether we add a pad field or not.
Extract the calculation into a helper and use it in both places.

Changes to desc.c
Changes-licensed-under: ISC

Changes to ath5k.h, base.c
Changes-licensed-under: 3-Clause-BSD

Signed-off-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

3 files changed, 11 insertions, 6 deletions

diff --git a/drivers/net/wireless/ath5k/ath5k.h b/drivers/net/wireless/ath5k/ath5k.h
index 13df1191b070..183ffc8e62ca 100644
--- a/drivers/net/wireless/ath5k/ath5k.h
+++ b/drivers/net/wireless/ath5k/ath5k.h
@@ -1350,4 +1350,9 @@ static inline u32 ath5k_hw_bitswap(u32 val, unsigned int bits)
         return retval;
 }
 
+static inline int ath5k_pad_size(int hdrlen)
+{
+        return (hdrlen < 24) ? 0 : hdrlen & 3;
+}
+
 #endif
diff --git a/drivers/net/wireless/ath5k/base.c b/drivers/net/wireless/ath5k/base.c
index 9b5f31aab574..4af2607deec0 100644
--- a/drivers/net/wireless/ath5k/base.c
+++ b/drivers/net/wireless/ath5k/base.c
@@ -1762,8 +1762,8 @@ accept:
                  * not try to remove padding from short control frames that do
                  * not have payload. */
                 hdrlen = ieee80211_get_hdrlen_from_skb(skb);
-                padsize = hdrlen & 3;
-                if (padsize && hdrlen >= 24) {
+                padsize = ath5k_pad_size(hdrlen);
+                if (padsize) {
                         memmove(skb->data + padsize, skb->data, hdrlen);
                         skb_pull(skb, padsize);
                 }
@@ -2638,8 +2638,8 @@ ath5k_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
          * if this is not the case we add the padding after the header
          */
         hdrlen = ieee80211_get_hdrlen_from_skb(skb);
-        padsize = hdrlen & 3;
-        if (padsize && hdrlen >= 24) {
+        padsize = ath5k_pad_size(hdrlen);
+        if (padsize) {
 
                 if (skb_headroom(skb) < padsize) {
                         ATH5K_ERR(sc, "tx hdrlen not %%4: %d not enough"
diff --git a/drivers/net/wireless/ath5k/desc.c b/drivers/net/wireless/ath5k/desc.c
index 5e362a7a3620..b40a9287a39a 100644
--- a/drivers/net/wireless/ath5k/desc.c
+++ b/drivers/net/wireless/ath5k/desc.c
@@ -71,7 +71,7 @@ ath5k_hw_setup_2word_tx_desc(struct ath5k_hw *ah, struct ath5k_desc *desc,
         /* Verify and set frame length */
 
         /* remove padding we might have added before */
-        frame_len = pkt_len - (hdr_len & 3) + FCS_LEN;
+        frame_len = pkt_len - ath5k_pad_size(hdr_len) + FCS_LEN;
 
         if (frame_len & ~AR5K_2W_TX_DESC_CTL0_FRAME_LEN)
                 return -EINVAL;
@@ -202,7 +202,7 @@ static int ath5k_hw_setup_4word_tx_desc(struct ath5k_hw *ah,
         /* Verify and set frame length */
 
         /* remove padding we might have added before */
-        frame_len = pkt_len - (hdr_len & 3) + FCS_LEN;
+        frame_len = pkt_len - ath5k_pad_size(hdr_len) + FCS_LEN;
 
         if (frame_len & ~AR5K_4W_TX_DESC_CTL0_FRAME_LEN)
                 return -EINVAL;