| From 77a861c405da75d81e9e6e32c50eb7f9777777e8 Mon Sep 17 00:00:00 2001 |
| From: Gertjan van Wingerde <gwingerde@gmail.com> |
| Date: Wed, 6 Jul 2011 22:56:24 +0200 |
| Subject: rt2x00: Serialize TX operations on a queue. |
| |
| From: Gertjan van Wingerde <gwingerde@gmail.com> |
| |
| commit 77a861c405da75d81e9e6e32c50eb7f9777777e8 upstream. |
| |
| 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@01019freenet.de> |
| Signed-off-by: Gertjan van Wingerde <gwingerde@gmail.com> |
| Acked-by: Helmut Schaa <helmut.schaa@googlemail.com> |
| Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com> |
| Signed-off-by: John W. Linville <linville@tuxdriver.com> |
| Cc: Tim Gardner <tim.gardner@canonical.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> |
| |
| --- |
| drivers/net/wireless/rt2x00/rt2x00queue.c | 21 ++++++++++++++++----- |
| drivers/net/wireless/rt2x00/rt2x00queue.h | 2 ++ |
| 2 files changed, 18 insertions(+), 5 deletions(-) |
| |
| --- a/drivers/net/wireless/rt2x00/rt2x00queue.c |
| +++ b/drivers/net/wireless/rt2x00/rt2x00queue.c |
| @@ -556,15 +556,21 @@ int rt2x00queue_write_tx_frame(struct da |
| 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, |
| @@ -573,7 +579,8 @@ int rt2x00queue_write_tx_frame(struct da |
| "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; |
| } |
| |
| /* |
| @@ -635,7 +642,8 @@ int rt2x00queue_write_tx_frame(struct da |
| 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); |
| @@ -644,7 +652,9 @@ int rt2x00queue_write_tx_frame(struct da |
| 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, |
| @@ -1185,6 +1195,7 @@ static void rt2x00queue_init(struct rt2x |
| 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; |
| --- 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; |