This is a note to let you know that I've just added the patch titled

    ath9k: fix invalid descriptor discarding

to the 3.13-stable tree which can be found at:
    
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     ath9k-fix-invalid-descriptor-discarding.patch
and it can be found in the queue-3.13 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From b7b146c9c9a0248cc57da71244f672ebc54bbef1 Mon Sep 17 00:00:00 2001
From: Felix Fietkau <n...@openwrt.org>
Date: Mon, 24 Feb 2014 22:26:06 +0100
Subject: ath9k: fix invalid descriptor discarding
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

From: Felix Fietkau <n...@openwrt.org>

commit b7b146c9c9a0248cc57da71244f672ebc54bbef1 upstream.

Only set sc->rx.discard_next to rx_stats->rs_more when actually
discarding the current descriptor.

Also, fix a detection of broken descriptors:
First the code checks if the current descriptor is not done.
Then it checks if the next descriptor is done.
Add a check that afterwards checks the first descriptor again, because
it might have been completed in the mean time.

This fixes a regression introduced in
commit 723e711356b5a8a95728a890e254e8b0d47b55cf
"ath9k: fix handling of broken descriptors"

Reported-by: Marco André Dinis <marcoandredi...@gmail.com>
Signed-off-by: Felix Fietkau <n...@openwrt.org>
Signed-off-by: John W. Linville <linvi...@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 drivers/net/wireless/ath/ath9k/recv.c |   70 +++++++++++++++++-----------------
 1 file changed, 35 insertions(+), 35 deletions(-)

--- a/drivers/net/wireless/ath/ath9k/recv.c
+++ b/drivers/net/wireless/ath/ath9k/recv.c
@@ -733,11 +733,18 @@ static struct ath_rxbuf *ath_get_next_rx
                        return NULL;
 
                /*
-                * mark descriptor as zero-length and set the 'more'
-                * flag to ensure that both buffers get discarded
+                * Re-check previous descriptor, in case it has been filled
+                * in the mean time.
                 */
-               rs->rs_datalen = 0;
-               rs->rs_more = true;
+               ret = ath9k_hw_rxprocdesc(ah, ds, rs);
+               if (ret == -EINPROGRESS) {
+                       /*
+                        * mark descriptor as zero-length and set the 'more'
+                        * flag to ensure that both buffers get discarded
+                        */
+                       rs->rs_datalen = 0;
+                       rs->rs_more = true;
+               }
        }
 
        list_del(&bf->list);
@@ -1166,32 +1173,32 @@ static int ath9k_rx_skb_preprocess(struc
        struct ath_common *common = ath9k_hw_common(ah);
        struct ieee80211_hdr *hdr;
        bool discard_current = sc->rx.discard_next;
-       int ret = 0;
 
        /*
         * Discard corrupt descriptors which are marked in
         * ath_get_next_rx_buf().
         */
-       sc->rx.discard_next = rx_stats->rs_more;
        if (discard_current)
-               return -EINVAL;
+               goto corrupt;
+
+       sc->rx.discard_next = false;
 
        /*
         * Discard zero-length packets.
         */
        if (!rx_stats->rs_datalen) {
                RX_STAT_INC(rx_len_err);
-               return -EINVAL;
+               goto corrupt;
        }
 
-        /*
-         * rs_status follows rs_datalen so if rs_datalen is too large
-         * we can take a hint that hardware corrupted it, so ignore
-         * those frames.
-         */
+       /*
+        * rs_status follows rs_datalen so if rs_datalen is too large
+        * we can take a hint that hardware corrupted it, so ignore
+        * those frames.
+        */
        if (rx_stats->rs_datalen > (common->rx_bufsize - 
ah->caps.rx_status_len)) {
                RX_STAT_INC(rx_len_err);
-               return -EINVAL;
+               goto corrupt;
        }
 
        /* Only use status info from the last fragment */
@@ -1205,10 +1212,8 @@ static int ath9k_rx_skb_preprocess(struc
         * This is different from the other corrupt descriptor
         * condition handled above.
         */
-       if (rx_stats->rs_status & ATH9K_RXERR_CORRUPT_DESC) {
-               ret = -EINVAL;
-               goto exit;
-       }
+       if (rx_stats->rs_status & ATH9K_RXERR_CORRUPT_DESC)
+               goto corrupt;
 
        hdr = (struct ieee80211_hdr *) (skb->data + ah->caps.rx_status_len);
 
@@ -1224,18 +1229,15 @@ static int ath9k_rx_skb_preprocess(struc
                if (ath_process_fft(sc, hdr, rx_stats, rx_status->mactime))
                        RX_STAT_INC(rx_spectral);
 
-               ret = -EINVAL;
-               goto exit;
+               return -EINVAL;
        }
 
        /*
         * everything but the rate is checked here, the rate check is done
         * separately to avoid doing two lookups for a rate for each frame.
         */
-       if (!ath9k_rx_accept(common, hdr, rx_status, rx_stats, decrypt_error)) {
-               ret = -EINVAL;
-               goto exit;
-       }
+       if (!ath9k_rx_accept(common, hdr, rx_status, rx_stats, decrypt_error))
+               return -EINVAL;
 
        rx_stats->is_mybeacon = ath9k_is_mybeacon(sc, hdr);
        if (rx_stats->is_mybeacon) {
@@ -1246,15 +1248,11 @@ static int ath9k_rx_skb_preprocess(struc
        /*
         * This shouldn't happen, but have a safety check anyway.
         */
-       if (WARN_ON(!ah->curchan)) {
-               ret = -EINVAL;
-               goto exit;
-       }
+       if (WARN_ON(!ah->curchan))
+               return -EINVAL;
 
-       if (ath9k_process_rate(common, hw, rx_stats, rx_status)) {
-               ret =-EINVAL;
-               goto exit;
-       }
+       if (ath9k_process_rate(common, hw, rx_stats, rx_status))
+               return -EINVAL;
 
        ath9k_process_rssi(common, hw, rx_stats, rx_status);
 
@@ -1269,9 +1267,11 @@ static int ath9k_rx_skb_preprocess(struc
                sc->rx.num_pkts++;
 #endif
 
-exit:
-       sc->rx.discard_next = false;
-       return ret;
+       return 0;
+
+corrupt:
+       sc->rx.discard_next = rx_stats->rs_more;
+       return -EINVAL;
 }
 
 static void ath9k_rx_skb_postprocess(struct ath_common *common,


Patches currently in stable-queue which might be from n...@openwrt.org are

queue-3.13/ath9k-fix-ps-poll-responses-under-a-mpdu-sessions.patch
queue-3.13/mac80211-send-control-port-protocol-frames-to-the-vo-queue.patch
queue-3.13/ath9k-fix-invalid-descriptor-discarding.patch
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