From: Gertjan van Wingerde <gwingerde@xxxxxxxxx>
The rt2x00 driver gets frequent occurrences of the following error message
when operating under load:
phy0 -> rt2x00queue_write_tx_frame: Error - Arrived at non-free entry in the
non-full queue 2.
This is caused by simultaneous attempts from mac80211 to send a frame via
rt2x00, which are not properly serialized inside rt2x00queue_write_tx_frame,
causing the second frame to fail sending with the above mentioned error
message.
Fix this by introducing a per-queue spinlock to serialize the TX operations
on that queue.
Reported-by: Andreas Hartmann <andihartmann@xxxxxxxxxxxxxxx>
Signed-off-by: Gertjan van Wingerde <gwingerde@xxxxxxxxx>
Acked-by: Helmut Schaa <helmut.schaa@xxxxxxxxxxxxxx>
Signed-off-by: Ivo van Doorn <IvDoorn@xxxxxxxxx>
---
drivers/net/wireless/rt2x00/rt2x00queue.c | 21 ++++++++++++++++-----
drivers/net/wireless/rt2x00/rt2x00queue.h | 2 ++
2 files changed, 18 insertions(+), 5 deletions(-)
diff --git a/drivers/net/wireless/rt2x00/rt2x00queue.c b/drivers/net/wireless/rt2x00/rt2x00queue.c
index c7fc9de..551cee1 100644
--- a/drivers/net/wireless/rt2x00/rt2x00queue.c
+++ b/drivers/net/wireless/rt2x00/rt2x00queue.c
@@ -555,15 +555,21 @@ int rt2x00queue_write_tx_frame(struct data_queue *queue, struct sk_buff *skb,
bool local)
{
struct ieee80211_tx_info *tx_info;
- struct queue_entry *entry = rt2x00queue_get_entry(queue, Q_INDEX);
+ struct queue_entry *entry;
struct txentry_desc txdesc;
struct skb_frame_desc *skbdesc;
u8 rate_idx, rate_flags;
+ int ret = 0;
+
+ spin_lock(&queue->tx_lock);
+
+ entry = rt2x00queue_get_entry(queue, Q_INDEX);
if (unlikely(rt2x00queue_full(queue))) {
ERROR(queue->rt2x00dev,
"Dropping frame due to full tx queue %d.\n", queue->qid);
- return -ENOBUFS;
+ ret = -ENOBUFS;
+ goto out;
}
if (unlikely(test_and_set_bit(ENTRY_OWNER_DEVICE_DATA,
@@ -572,7 +578,8 @@ int rt2x00queue_write_tx_frame(struct data_queue *queue, struct sk_buff *skb,
"Arrived at non-free entry in the non-full queue %d.\n"
"Please file bug report to %s.\n",
queue->qid, DRV_PROJECT);
- return -EINVAL;
+ ret = -EINVAL;
+ goto out;
}
/*
@@ -634,7 +641,8 @@ int rt2x00queue_write_tx_frame(struct data_queue *queue, struct sk_buff *skb,
if (unlikely(rt2x00queue_write_tx_data(entry, &txdesc))) {
clear_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags);
entry->skb = NULL;
- return -EIO;
+ ret = -EIO;
+ goto out;
}
set_bit(ENTRY_DATA_PENDING, &entry->flags);
@@ -643,7 +651,9 @@ int rt2x00queue_write_tx_frame(struct data_queue *queue, struct sk_buff *skb,
rt2x00queue_write_tx_descriptor(entry, &txdesc);
rt2x00queue_kick_tx_queue(queue, &txdesc);
- return 0;
+out:
+ spin_unlock(&queue->tx_lock);
+ return ret;
}
int rt2x00queue_clear_beacon(struct rt2x00_dev *rt2x00dev,
@@ -1184,6 +1194,7 @@ static void rt2x00queue_init(struct rt2x00_dev *rt2x00dev,
struct data_queue *queue, enum data_queue_qid qid)
{
mutex_init(&queue->status_lock);
+ spin_lock_init(&queue->tx_lock);
spin_lock_init(&queue->index_lock);
queue->rt2x00dev = rt2x00dev;
diff --git a/drivers/net/wireless/rt2x00/rt2x00queue.h b/drivers/net/wireless/rt2x00/rt2x00queue.h
index 5900474..f2100f4 100644
--- a/drivers/net/wireless/rt2x00/rt2x00queue.h
+++ b/drivers/net/wireless/rt2x00/rt2x00queue.h
@@ -432,6 +432,7 @@ enum data_queue_flags {
* @flags: Entry flags, see &enum queue_entry_flags.
* @status_lock: The mutex for protecting the start/stop/flush
* handling on this queue.
+ * @tx_lock: Spinlock to serialize tx operations on this queue.
* @index_lock: Spinlock to protect index handling. Whenever @index, @index_done or
* @index_crypt needs to be changed this lock should be grabbed to prevent
* index corruption due to concurrency.
@@ -458,6 +459,7 @@ struct data_queue {
unsigned long flags;
struct mutex status_lock;
+ spinlock_t tx_lock;
spinlock_t index_lock;
unsigned int count;
--
1.7.2.3
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