From b967613d7e7c7bad176f5627c55e2d8c5aa2480e Mon Sep 17 00:00:00 2001 From: Emmanuel Grumbach Date: Thu, 13 Jun 2013 11:45:59 +0300 Subject: [PATCH] iwlwifi: pcie: fix race in queue unmapping 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. Cc: stable@vger.kernel.org Signed-off-by: Emmanuel Grumbach Signed-off-by: Johannes Berg --- drivers/net/wireless/iwlwifi/pcie/tx.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/net/wireless/iwlwifi/pcie/tx.c b/drivers/net/wireless/iwlwifi/pcie/tx.c index c5e30294c5ac..51fca425def7 100644 --- 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 iwl_trans *trans, int txq_id) 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_trans *trans, int txq_id, int ssn, 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 iwl_trans *trans, int txq_id, int fifo, (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); } -- 2.30.2