[3.11.y.z extended stable] Patch "Revert "mac80211: move "bufferable MMPDU" check to fix AP mode scan"" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    Revert "mac80211: move "bufferable MMPDU" check to fix AP mode scan"

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 6e8befaa6ea1b8d8d3cbdf557449e007b7f729f5 Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg at intel.com>
Date: Mon, 7 Jul 2014 12:01:11 +0200
Subject: Revert "mac80211: move "bufferable MMPDU" check to fix AP mode scan"

commit 08b9939997df30e42a228e1ecb97f99e9c8ea84e upstream.

This reverts commit 277d916fc2e959c3f106904116bb4f7b1148d47a as it was
at least breaking iwlwifi by setting the IEEE80211_TX_CTL_NO_PS_BUFFER
flag in all kinds of interface modes, not only for AP mode where it is
appropriate.

To avoid reintroducing the original problem, explicitly check for probe
request frames in the multicast buffering code.

Fixes: 277d916fc2e9 ("mac80211: move "bufferable MMPDU" check to fix AP mode scan")
Signed-off-by: Johannes Berg <johannes.berg at intel.com>
[ luis: backported to 3.11: based on Johannes' backport for 3.10 ]
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 net/mac80211/tx.c | 26 +++++++++++++-------------
 1 file changed, 13 insertions(+), 13 deletions(-)

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 5fd26c6bad2a..cc3be10bab23 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -398,6 +398,9 @@ ieee80211_tx_h_multicast_ps_buf(struct ieee80211_tx_data *tx)
 	if (ieee80211_has_order(hdr->frame_control))
 		return TX_CONTINUE;

+	if (ieee80211_is_probe_req(hdr->frame_control))
+		return TX_CONTINUE;
+
 	if (tx->local->hw.flags & IEEE80211_HW_QUEUE_CONTROL)
 		info->hw_queue = tx->sdata->vif.cab_queue;

@@ -448,6 +451,7 @@ ieee80211_tx_h_unicast_ps_buf(struct ieee80211_tx_data *tx)
 {
 	struct sta_info *sta = tx->sta;
 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
+	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
 	struct ieee80211_local *local = tx->local;

 	if (unlikely(!sta))
@@ -458,6 +462,15 @@ ieee80211_tx_h_unicast_ps_buf(struct ieee80211_tx_data *tx)
 		     !(info->flags & IEEE80211_TX_CTL_NO_PS_BUFFER))) {
 		int ac = skb_get_queue_mapping(tx->skb);

+		/* only deauth, disassoc and action are bufferable MMPDUs */
+		if (ieee80211_is_mgmt(hdr->frame_control) &&
+		    !ieee80211_is_deauth(hdr->frame_control) &&
+		    !ieee80211_is_disassoc(hdr->frame_control) &&
+		    !ieee80211_is_action(hdr->frame_control)) {
+			info->flags |= IEEE80211_TX_CTL_NO_PS_BUFFER;
+			return TX_CONTINUE;
+		}
+
 		ps_dbg(sta->sdata, "STA %pM aid %d: PS buffer for AC %d\n",
 		       sta->sta.addr, sta->sta.aid, ac);
 		if (tx->local->total_ps_buffered >= TOTAL_MAX_TX_BUFFER)
@@ -515,22 +528,9 @@ ieee80211_tx_h_unicast_ps_buf(struct ieee80211_tx_data *tx)
 static ieee80211_tx_result debug_noinline
 ieee80211_tx_h_ps_buf(struct ieee80211_tx_data *tx)
 {
-	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
-	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
-
 	if (unlikely(tx->flags & IEEE80211_TX_PS_BUFFERED))
 		return TX_CONTINUE;

-	/* only deauth, disassoc and action are bufferable MMPDUs */
-	if (ieee80211_is_mgmt(hdr->frame_control) &&
-	    !ieee80211_is_deauth(hdr->frame_control) &&
-	    !ieee80211_is_disassoc(hdr->frame_control) &&
-	    !ieee80211_is_action(hdr->frame_control)) {
-		if (tx->flags & IEEE80211_TX_UNICAST)
-			info->flags |= IEEE80211_TX_CTL_NO_PS_BUFFER;
-		return TX_CONTINUE;
-	}
-
 	if (tx->flags & IEEE80211_TX_UNICAST)
 		return ieee80211_tx_h_unicast_ps_buf(tx);
 	else
--
1.9.1