[PATCH 4.8 40/67] iwlwifi: pcie: mark command queue lock with separate lockdep class
From: Greg Kroah-Hartman
Date: Thu Nov 24 2016 - 10:29:37 EST
4.8-stable review patch. If anyone has any objections, please let me know.
------------------
From: Johannes Berg <johannes.berg@xxxxxxxxx>
commit faead41cc7213ccef5a58c1bf518ac24816fe8a6 upstream.
Emmanuel reports that when CMD_WANT_ASYNC_CALLBACK is used by mvm,
the callback will be called with the command queue lock held, and
mvm will try to stop all (other) TX queues, which acquires their
locks - this caused a false lockdep recursive locking report.
Suppress this report by marking the command queue lock with a new,
separate, lock class so lockdep can tell the difference between
the two types of queues.
Fixes: 156f92f2b471 ("iwlwifi: block the queues when we send ADD_STA for uAPSD")
Reported-by: Emmanuel Grumbach <emmanuel.grumbach@xxxxxxxxx>
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Signed-off-by: Luca Coelho <luciano.coelho@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/wireless/intel/iwlwifi/pcie/tx.c | 8 ++++++++
1 file changed, 8 insertions(+)
--- a/drivers/net/wireless/intel/iwlwifi/pcie/tx.c
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/tx.c
@@ -522,6 +522,7 @@ error:
static int iwl_pcie_txq_init(struct iwl_trans *trans, struct iwl_txq *txq,
int slots_num, u32 txq_id)
{
+ struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
int ret;
txq->need_update = false;
@@ -536,6 +537,13 @@ static int iwl_pcie_txq_init(struct iwl_
return ret;
spin_lock_init(&txq->lock);
+
+ if (txq_id == trans_pcie->cmd_queue) {
+ static struct lock_class_key iwl_pcie_cmd_queue_lock_class;
+
+ lockdep_set_class(&txq->lock, &iwl_pcie_cmd_queue_lock_class);
+ }
+
__skb_queue_head_init(&txq->overflow_q);
/*