From b967613d7e7c7bad176f5627c55e2d8c5aa2480e Mon Sep 17 00:00:00 2001 From: Emmanuel Grumbach Date: Thu, 13 Jun 2013 11:45:59 +0300 Subject: [PATCH 1/2] 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); } From 8a487b1a7432b20ff3f82387a8ce7555a964b44e Mon Sep 17 00:00:00 2001 From: Emmanuel Grumbach Date: Thu, 13 Jun 2013 13:10:00 +0300 Subject: [PATCH 2/2] iwlwifi: pcie: wake the queue if stopped when being unmapped When the queue is unmapped while it was so loaded that mac80211's was stopped, we need to wake the queue after having freed all the packets in the queue. Not doing so can result in weird stuff like: * run lots of traffic (mac80211's queue gets stopped) * RFKILL * de-assert RFKILL * no traffic Cc: stable@vger.kernel.org Signed-off-by: Emmanuel Grumbach Signed-off-by: Johannes Berg --- drivers/net/wireless/iwlwifi/pcie/tx.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/net/wireless/iwlwifi/pcie/tx.c b/drivers/net/wireless/iwlwifi/pcie/tx.c index 51fca425def7..48acfc620191 100644 --- a/drivers/net/wireless/iwlwifi/pcie/tx.c +++ b/drivers/net/wireless/iwlwifi/pcie/tx.c @@ -583,6 +583,9 @@ static void iwl_pcie_txq_unmap(struct iwl_trans *trans, int txq_id) } txq->active = false; spin_unlock_bh(&txq->lock); + + /* just in case - this queue may have been stopped */ + iwl_wake_queue(trans, txq); } /*