This is a note to let you know that I've just added the patch titled
iwlwifi: pcie: fix race in queue unmapping
to the 3.10-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:
iwlwifi-pcie-fix-race-in-queue-unmapping.patch
and it can be found in the queue-3.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From b967613d7e7c7bad176f5627c55e2d8c5aa2480e Mon Sep 17 00:00:00 2001
From: Emmanuel Grumbach <emmanuel.grumbach@xxxxxxxxx>
Date: Thu, 13 Jun 2013 11:45:59 +0300
Subject: iwlwifi: pcie: fix race in queue unmapping
From: Emmanuel Grumbach <emmanuel.grumbach@xxxxxxxxx>
commit b967613d7e7c7bad176f5627c55e2d8c5aa2480e upstream.
When a queue is disabled, it frees all its entries. Later,
the op_mode might still get notifications from the firmware
that triggers to free entries in the tx queue. The transport
should be prepared for these races and know to ignore
reclaim calls on queues that have been disabled and whose
entries have been freed.
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@xxxxxxxxx>
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/wireless/iwlwifi/pcie/tx.c | 10 ++++++++++
1 file changed, 10 insertions(+)
--- a/drivers/net/wireless/iwlwifi/pcie/tx.c
+++ b/drivers/net/wireless/iwlwifi/pcie/tx.c
@@ -576,9 +576,12 @@ static void iwl_pcie_txq_unmap(struct iw
spin_lock_bh(&txq->lock);
while (q->write_ptr != q->read_ptr) {
+ IWL_DEBUG_TX_REPLY(trans, "Q %d Free %d\n",
+ txq_id, q->read_ptr);
iwl_pcie_txq_free_tfd(trans, txq);
q->read_ptr = iwl_queue_inc_wrap(q->read_ptr, q->n_bd);
}
+ txq->active = false;
spin_unlock_bh(&txq->lock);
}
@@ -927,6 +930,12 @@ void iwl_trans_pcie_reclaim(struct iwl_t
spin_lock_bh(&txq->lock);
+ if (!txq->active) {
+ IWL_DEBUG_TX_QUEUES(trans, "Q %d inactive - ignoring idx %d\n",
+ txq_id, ssn);
+ goto out;
+ }
+
if (txq->q.read_ptr == tfd_num)
goto out;
@@ -1103,6 +1112,7 @@ void iwl_trans_pcie_txq_enable(struct iw
(fifo << SCD_QUEUE_STTS_REG_POS_TXF) |
(1 << SCD_QUEUE_STTS_REG_POS_WSL) |
SCD_QUEUE_STTS_REG_MSK);
+ trans_pcie->txq[txq_id].active = true;
IWL_DEBUG_TX_QUEUES(trans, "Activate queue %d on FIFO %d WrPtr: %d\n",
txq_id, fifo, ssn & 0xff);
}
Patches currently in stable-queue which might be from emmanuel.grumbach@xxxxxxxxx are
queue-3.10/iwlwifi-pcie-fix-race-in-queue-unmapping.patch
queue-3.10/iwlwifi-pcie-wake-the-queue-if-stopped-when-being-unmapped.patch
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