mwifiex: adding check for enough space before padding

All MSDUs, except the last one in an AMSDU, should end up at 4
bytes boundary. There is need to check if enough skb_tailroom
space exists before padding the skb.

Also re-arranging code for better readablity.

Signed-off-by: Yogesh Ashok Powar <yogeshp@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 14 insertions, 8 deletions

diff --git a/drivers/net/wireless/mwifiex/11n_aggr.c b/drivers/net/wireless/mwifiex/11n_aggr.c
index aee3491f61d5..25312e4437f5 100644
--- a/drivers/net/wireless/mwifiex/11n_aggr.c
+++ b/drivers/net/wireless/mwifiex/11n_aggr.c
@@ -185,16 +185,15 @@ mwifiex_11n_aggregate_pkt(struct mwifiex_private *priv,
         tx_info_aggr->bss_index = tx_info_src->bss_index;
         skb_aggr->priority = skb_src->priority;
 
-        while (skb_src && ((skb_headroom(skb_aggr) + skb_src->len
-                                        + LLC_SNAP_LEN)
-                                <= adapter->tx_buf_size)) {
+        do {
+                /* Check if AMSDU can accommodate this MSDU */
+                if (skb_tailroom(skb_aggr) < (skb_src->len + LLC_SNAP_LEN))
+                        break;
 
                 skb_src = skb_dequeue(&pra_list->skb_head);
 
-                if (skb_src) {
-                        pra_list->total_pkts_size -= skb_src->len;
-                        pra_list->total_pkts--;
-                }
+                pra_list->total_pkts_size -= skb_src->len;
+                pra_list->total_pkts--;
 
                 atomic_dec(&priv->wmm.tx_pkts_queued);
 
@@ -212,8 +211,15 @@ mwifiex_11n_aggregate_pkt(struct mwifiex_private *priv,
                         return -1;
                 }
 
+                if (skb_tailroom(skb_aggr) < pad) {
+                        pad = 0;
+                        break;
+                }
+                skb_put(skb_aggr, pad);
+
                 skb_src = skb_peek(&pra_list->skb_head);
-        }
+
+        } while (skb_src);
 
         spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock, ra_list_flags);