2013-02-13 16:55:47

by Johannes Berg

Subject: [PATCH] mac80211: use spin_lock_bh() for tim_lock

From: Johannes Berg <[email protected]>

There's no need to use _irqsave() as the lock
is never used in interrupt context.

This also fixes a problem in the iwlwifi MVM
driver that calls spin_unlock_bh() within its
set_tim() callback.

Signed-off-by: Johannes Berg <[email protected]>
---
net/mac80211/sta_info.c | 5 ++---
net/mac80211/tx.c | 6 ++----
2 files changed, 4 insertions(+), 7 deletions(-)

diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index 07b312e..8c91154 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -573,7 +573,6 @@ void sta_info_recalc_tim(struct sta_info *sta)
{
struct ieee80211_local *local = sta->local;
struct ps_data *ps;
- unsigned long flags;
bool indicate_tim = false;
u8 ignore_for_tim = sta->sta.uapsd_queues;
int ac;
@@ -630,7 +629,7 @@ void sta_info_recalc_tim(struct sta_info *sta)
}

done:
- spin_lock_irqsave(&local->tim_lock, flags);
+ spin_lock_bh(&local->tim_lock);

if (indicate_tim)
__bss_tim_set(ps->tim, id);
@@ -643,7 +642,7 @@ void sta_info_recalc_tim(struct sta_info *sta)
local->tim_in_locked_section = false;
}

- spin_unlock_irqrestore(&local->tim_lock, flags);
+ spin_unlock_bh(&local->tim_lock);
}

static bool sta_info_buffer_expired(struct sta_info *sta, struct sk_buff *skb)
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index eef720d..6fdab27 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -2365,11 +2365,9 @@ static int ieee80211_beacon_add_tim(struct ieee80211_sub_if_data *sdata,
if (local->tim_in_locked_section) {
__ieee80211_beacon_add_tim(sdata, ps, skb);
} else {
- unsigned long flags;
-
- spin_lock_irqsave(&local->tim_lock, flags);
+ spin_lock(&local->tim_lock);
__ieee80211_beacon_add_tim(sdata, ps, skb);
- spin_unlock_irqrestore(&local->tim_lock, flags);
+ spin_unlock(&local->tim_lock);
}

return 0;
--
1.8.0

2013-02-14 17:36:14

by Johannes Berg

Subject: Re: [PATCH] mac80211: use spin_lock_bh() for tim_lock

On Wed, 2013-02-13 at 17:55 +0100, Johannes Berg wrote:
> From: Johannes Berg <[email protected]>
>
> There's no need to use _irqsave() as the lock
> is never used in interrupt context.
>
> This also fixes a problem in the iwlwifi MVM
> driver that calls spin_unlock_bh() within its
> set_tim() callback.

Applied.

johannes