ath9k: fix filtering out multi-descriptor frames, which can cause issues with 11n links because of bogus rx status data

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@21351 3c298f89-4303-0410-b956-a3cf2f4a3e73

package/mac80211/patches/550-ath9k_no_multi_desc_frames.patch

@@ -0,0 +1,24 @@
+--- a/drivers/net/wireless/ath/ath9k/common.c
++++ b/drivers/net/wireless/ath/ath9k/common.c
+@@ -57,13 +57,19 @@ static bool ath9k_rx_accept(struct ath_c
+ 	 * rs_more indicates chained descriptors which can be used
+ 	 * to link buffers together for a sort of scatter-gather
+ 	 * operation.
+-	 *
++	 * reject the frame, we don't support scatter-gather yet and
++	 * the frame is probably corrupt anyway
++	 */
++	if (rx_stats->rs_more)
++		return false;
++
++	/*
+ 	 * The rx_stats->rs_status will not be set until the end of the
+ 	 * chained descriptors so it can be ignored if rs_more is set. The
+ 	 * rs_more will be false at the last element of the chained
+ 	 * descriptors.
+ 	 */
+-	if (!rx_stats->rs_more && rx_stats->rs_status != 0) {
++	if (rx_stats->rs_status != 0) {
+ 		if (rx_stats->rs_status & ATH9K_RXERR_CRC)
+ 			rxs->flag |= RX_FLAG_FAILED_FCS_CRC;
+ 		if (rx_stats->rs_status & ATH9K_RXERR_PHY)