iwlwifi: mvm: avoid possible deadlock in TX path

iwl_mvm_tx_mpdu() may run from iwl_mvm_add_new_dqa_stream_wk(), where
soft-IRQs aren't disabled. In this case, it may hold the station lock
and be interrupted by a soft-IRQ that also wants to acquire said lock,
leading to a deadlock.

Fix it by disabling soft-IRQs in iwl_mvm_add_new_dqa_stream_wk().

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/sta.c b/drivers/net/wireless/intel/iwlwifi/mvm/sta.c
index db26f00..98d123d 100644 (file)
--- a/drivers/net/wireless/intel/iwlwifi/mvm/sta.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/sta.c
@@ -1399,7 +1399,9 @@ void iwl_mvm_add_new_dqa_stream_wk(struct work_struct *wk)
 
                iwl_mvm_sta_alloc_queue(mvm, txq->sta, txq->ac, tid);
                list_del_init(&mvmtxq->list);
+               local_bh_disable();
                iwl_mvm_mac_itxq_xmit(mvm->hw, txq);
+               local_bh_enable();
        }
 
        mutex_unlock(&mvm->mutex);