[4.2.y-ckt stable] Patch "iwlwifi: mvm: inc pending frames counter also when txing non-sta" has been added to the 4.2.y-ckt tree

[Kamal Mostafa]

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

    iwlwifi: mvm: inc pending frames counter also when txing non-sta

to the linux-4.2.y-queue branch of the 4.2.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-4.2.y-queue

This patch is scheduled to be released in version 4.2.8-ckt6.

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

For more information about the 4.2.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

---8<------------------------------------------------------------

>From 1ddea5ad8b6ece1355a8486239f83cc9173944c1 Mon Sep 17 00:00:00 2001
From: Liad Kaufman <liad.kaufman at intel.com>
Date: Sun, 14 Feb 2016 15:32:58 +0200
Subject: iwlwifi: mvm: inc pending frames counter also when txing non-sta

commit fb896c44f88a75843a072cd6961b1615732f7811 upstream.

Until this patch, when TXing non-sta the pending_frames counter
wasn't increased, but it WAS decreased in
iwl_mvm_rx_tx_cmd_single(), what makes it negative in certain
conditions. This in turn caused much trouble when we need to
remove the station since we won't be waiting forever until
pending_frames gets 0. In certain cases, we were exhausting
the station table even in BSS mode, because we had a lot of
stale stations.

Increase the counter also in iwl_mvm_tx_skb_non_sta() after a
successful TX to avoid this outcome.

Signed-off-by: Liad Kaufman <liad.kaufman at intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach at intel.com>
[ kamal: backport to 4.2: file rename ]
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/net/wireless/iwlwifi/mvm/tx.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/net/wireless/iwlwifi/mvm/tx.c b/drivers/net/wireless/iwlwifi/mvm/tx.c
index 89116864..998f0ef 100644
--- a/drivers/net/wireless/iwlwifi/mvm/tx.c
+++ b/drivers/net/wireless/iwlwifi/mvm/tx.c
@@ -397,6 +397,15 @@ int iwl_mvm_tx_skb_non_sta(struct iwl_mvm *mvm, struct sk_buff *skb)
 		return -1;
 	}

+	/*
+	 * Increase the pending frames counter, so that later when a reply comes
+	 * in and the counter is decreased - we don't start getting negative
+	 * values.
+	 * Note that we don't need to make sure it isn't agg'd, since we're
+	 * TXing non-sta
+	 */
+	atomic_inc(&mvm->pending_frames[sta_id]);
+
 	return 0;
 }

--
2.7.0