lkml.org 
[lkml]   [2013]   [Jul]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[ 43/72] iwlwifi: pcie: fix race in queue unmapping
Date
3.10-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

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@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
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);
}



\
 
 \ /
  Last update: 2013-07-19 08:22    [W:0.306 / U:0.368 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site