From: Sara Sharon <sara.sharon@intel.com>
Date: Sun, 9 Oct 2016 14:34:24 +0000 (+0300)
Subject: iwlwifi: mvm: wake the wait queue when the RX sync counter is zero
X-Git-Tag: v4.8.11~25
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=545ea4003db9b73a5d29a4dd0d140382a8de85bd;p=thirdparty%2Fkernel%2Fstable.git

iwlwifi: mvm: wake the wait queue when the RX sync counter is zero

commit 3a732c65de427fdae67a243fd331356034b5a1e8 upstream.

When we sync the RX queues the driver waits to receive echo
notification on all the RX queues.
The wait queue is set with timeout until all queues have received
the notification.
However, iwl_mvm_rx_queue_notif() never woke up the wait queue,
with the result of the counter value being checked only when the
timeout expired.
This may cause a latency of up to 1 second.

Fixes: 0636b938214c ("iwlwifi: mvm: implement driver RX queues sync command")
Signed-off-by: Sara Sharon <sara.sharon@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c b/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
index 5dd77e3366172..90a1f4a06ba1b 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
@@ -4097,7 +4097,6 @@ void iwl_mvm_sync_rx_queues_internal(struct iwl_mvm *mvm,
 				     struct iwl_mvm_internal_rxq_notif *notif,
 				     u32 size)
 {
-	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(notif_waitq);
 	u32 qmask = BIT(mvm->trans->num_rx_queues) - 1;
 	int ret;
 
@@ -4119,7 +4118,7 @@ void iwl_mvm_sync_rx_queues_internal(struct iwl_mvm *mvm,
 	}
 
 	if (notif->sync)
-		ret = wait_event_timeout(notif_waitq,
+		ret = wait_event_timeout(mvm->rx_sync_waitq,
 					 atomic_read(&mvm->queue_sync_counter) == 0,
 					 HZ);
 	WARN_ON_ONCE(!ret);
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h b/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h
index 6a615bb730425..e9cb970139c7b 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h
@@ -932,6 +932,7 @@ struct iwl_mvm {
 	/* sync d0i3_tx queue and IWL_MVM_STATUS_IN_D0I3 status flag */
 	spinlock_t d0i3_tx_lock;
 	wait_queue_head_t d0i3_exit_waitq;
+	wait_queue_head_t rx_sync_waitq;
 
 	/* BT-Coex */
 	struct iwl_bt_coex_profile_notif last_bt_notif;
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/ops.c b/drivers/net/wireless/intel/iwlwifi/mvm/ops.c
index 55d9096da68c2..30bbdec97d03b 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/ops.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/ops.c
@@ -618,6 +618,7 @@ iwl_op_mode_mvm_start(struct iwl_trans *trans, const struct iwl_cfg *cfg,
 	spin_lock_init(&mvm->refs_lock);
 	skb_queue_head_init(&mvm->d0i3_tx);
 	init_waitqueue_head(&mvm->d0i3_exit_waitq);
+	init_waitqueue_head(&mvm->rx_sync_waitq);
 
 	atomic_set(&mvm->queue_sync_counter, 0);
 
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c b/drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c
index afb7eb60e4540..2b994be10b425 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c
@@ -545,7 +545,8 @@ void iwl_mvm_rx_queue_notif(struct iwl_mvm *mvm, struct iwl_rx_cmd_buffer *rxb,
 				  "Received expired RX queue sync message\n");
 			return;
 		}
-		atomic_dec(&mvm->queue_sync_counter);
+		if (!atomic_dec_return(&mvm->queue_sync_counter))
+			wake_up(&mvm->rx_sync_waitq);
 	}
 
 	switch (internal_notif->type) {