mirror of
https://git.yoctoproject.org/meta-ti
synced 2026-07-21 03:17:18 +00:00
Koen Kooi
7df8fc578b
Signed-off-by: Koen Kooi <koen@dominion.thruhere.net> Signed-off-by: Denys Dmytriyenko <denys@ti.com>
100 lines
3.8 KiB
Diff
100 lines
3.8 KiB
Diff
From c27583afc5c12c3731697b41e6a7c4fa2a239fae Mon Sep 17 00:00:00 2001
|
|
From: Stanislaw Gruszka <sgruszka@redhat.com>
|
|
Date: Fri, 9 Mar 2012 12:39:54 +0100
|
|
Subject: [PATCH 08/42] rt2x00: fix random stalls
|
|
|
|
commit 3780d038fdf4b5ef26ead10b0604ab1f46dd9510 upstream.
|
|
|
|
Is possible that we stop queue and then do not wake up it again,
|
|
especially when packets are transmitted fast. That can be easily
|
|
reproduced with modified tx queue entry_num to some small value e.g. 16.
|
|
|
|
If mac80211 already hold local->queue_stop_reason_lock, then we can wait
|
|
on that lock in both rt2x00queue_pause_queue() and
|
|
rt2x00queue_unpause_queue(). After drooping ->queue_stop_reason_lock
|
|
is possible that __ieee80211_wake_queue() will be performed before
|
|
__ieee80211_stop_queue(), hence we stop queue and newer wake up it
|
|
again.
|
|
|
|
Another race condition is possible when between rt2x00queue_threshold()
|
|
check and rt2x00queue_pause_queue() we will process all pending tx
|
|
buffers on different cpu. This might happen if for example interrupt
|
|
will be triggered on cpu performing rt2x00mac_tx().
|
|
|
|
To prevent race conditions serialize pause/unpause by queue->tx_lock.
|
|
|
|
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
|
|
Acked-by: Gertjan van Wingerde <gwingerde@gmail.com>
|
|
Signed-off-by: John W. Linville <linville@tuxdriver.com>
|
|
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
---
|
|
drivers/net/wireless/rt2x00/rt2x00dev.c | 6 +++++-
|
|
drivers/net/wireless/rt2x00/rt2x00mac.c | 9 +++++++++
|
|
drivers/net/wireless/rt2x00/rt2x00queue.c | 3 +++
|
|
3 files changed, 17 insertions(+), 1 deletion(-)
|
|
|
|
diff --git a/drivers/net/wireless/rt2x00/rt2x00dev.c b/drivers/net/wireless/rt2x00/rt2x00dev.c
|
|
index edd317f..21b529b 100644
|
|
--- a/drivers/net/wireless/rt2x00/rt2x00dev.c
|
|
+++ b/drivers/net/wireless/rt2x00/rt2x00dev.c
|
|
@@ -426,10 +426,14 @@ void rt2x00lib_txdone(struct queue_entry *entry,
|
|
/*
|
|
* If the data queue was below the threshold before the txdone
|
|
* handler we must make sure the packet queue in the mac80211 stack
|
|
- * is reenabled when the txdone handler has finished.
|
|
+ * is reenabled when the txdone handler has finished. This has to be
|
|
+ * serialized with rt2x00mac_tx(), otherwise we can wake up queue
|
|
+ * before it was stopped.
|
|
*/
|
|
+ spin_lock_bh(&entry->queue->tx_lock);
|
|
if (!rt2x00queue_threshold(entry->queue))
|
|
rt2x00queue_unpause_queue(entry->queue);
|
|
+ spin_unlock_bh(&entry->queue->tx_lock);
|
|
}
|
|
EXPORT_SYMBOL_GPL(rt2x00lib_txdone);
|
|
|
|
diff --git a/drivers/net/wireless/rt2x00/rt2x00mac.c b/drivers/net/wireless/rt2x00/rt2x00mac.c
|
|
index bf0acff..373dae1 100644
|
|
--- a/drivers/net/wireless/rt2x00/rt2x00mac.c
|
|
+++ b/drivers/net/wireless/rt2x00/rt2x00mac.c
|
|
@@ -152,13 +152,22 @@ void rt2x00mac_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
|
|
if (unlikely(rt2x00queue_write_tx_frame(queue, skb, false)))
|
|
goto exit_fail;
|
|
|
|
+ /*
|
|
+ * Pausing queue has to be serialized with rt2x00lib_txdone(). Note
|
|
+ * we should not use spin_lock_bh variant as bottom halve was already
|
|
+ * disabled before ieee80211_xmit() call.
|
|
+ */
|
|
+ spin_lock(&queue->tx_lock);
|
|
if (rt2x00queue_threshold(queue))
|
|
rt2x00queue_pause_queue(queue);
|
|
+ spin_unlock(&queue->tx_lock);
|
|
|
|
return;
|
|
|
|
exit_fail:
|
|
+ spin_lock(&queue->tx_lock);
|
|
rt2x00queue_pause_queue(queue);
|
|
+ spin_unlock(&queue->tx_lock);
|
|
exit_free_skb:
|
|
dev_kfree_skb_any(skb);
|
|
}
|
|
diff --git a/drivers/net/wireless/rt2x00/rt2x00queue.c b/drivers/net/wireless/rt2x00/rt2x00queue.c
|
|
index 5adfb3e..9b1b2b7 100644
|
|
--- a/drivers/net/wireless/rt2x00/rt2x00queue.c
|
|
+++ b/drivers/net/wireless/rt2x00/rt2x00queue.c
|
|
@@ -619,6 +619,9 @@ int rt2x00queue_write_tx_frame(struct data_queue *queue, struct sk_buff *skb,
|
|
else if (test_bit(REQUIRE_DMA, &queue->rt2x00dev->cap_flags))
|
|
rt2x00queue_align_frame(skb);
|
|
|
|
+ /*
|
|
+ * That function must be called with bh disabled.
|
|
+ */
|
|
spin_lock(&queue->tx_lock);
|
|
|
|
if (unlikely(rt2x00queue_full(queue))) {
|
|
--
|
|
1.7.9.4
|
|
|