mac80211: don't check rates on PLCP error frames

Frames that failed PLCP error checks are most likely
microwave transmissions (well, maybe not ...) and
don't have a proper rate detected, so ignore it.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 29 insertions, 20 deletions

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index fa0f37e4afe4..225e8ee682e3 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -2615,28 +2615,37 @@ void ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb)
         if (WARN_ON(!local->started))
                 goto drop;
 
-        if (status->flag & RX_FLAG_HT) {
+        if (likely(!(status->flag & RX_FLAG_FAILED_PLCP_CRC))) {
                 /*
-                 * rate_idx is MCS index, which can be [0-76] as documented on:
-                 *
-                 * http://wireless.kernel.org/en/developers/Documentation/ieee80211/802.11n
-                 *
-                 * Anything else would be some sort of driver or hardware error.
-                 * The driver should catch hardware errors.
+                 * Validate the rate, unless a PLCP error means that
+                 * we probably can't have a valid rate here anyway.
                  */
-                if (WARN((status->rate_idx < 0 ||
-                         status->rate_idx > 76),
-                         "Rate marked as an HT rate but passed "
-                         "status->rate_idx is not "
-                         "an MCS index [0-76]: %d (0x%02x)\n",
-                         status->rate_idx,
-                         status->rate_idx))
-                        goto drop;
-        } else {
-                if (WARN_ON(status->rate_idx < 0 ||
-                            status->rate_idx >= sband->n_bitrates))
-                        goto drop;
-                rate = &sband->bitrates[status->rate_idx];
+
+                if (status->flag & RX_FLAG_HT) {
+                        /*
+                         * rate_idx is MCS index, which can be [0-76]
+                         * as documented on:
+                         *
+                         * http://wireless.kernel.org/en/developers/Documentation/ieee80211/802.11n
+                         *
+                         * Anything else would be some sort of driver or
+                         * hardware error. The driver should catch hardware
+                         * errors.
+                         */
+                        if (WARN((status->rate_idx < 0 ||
+                                 status->rate_idx > 76),
+                                 "Rate marked as an HT rate but passed "
+                                 "status->rate_idx is not "
+                                 "an MCS index [0-76]: %d (0x%02x)\n",
+                                 status->rate_idx,
+                                 status->rate_idx))
+                                goto drop;
+                } else {
+                        if (WARN_ON(status->rate_idx < 0 ||
+                                    status->rate_idx >= sband->n_bitrates))
+                                goto drop;
+                        rate = &sband->bitrates[status->rate_idx];
+                }
         }
 
         /*