[PATCH] clk: Silence warnings about lock imbalances

From: Stephen Boyd
Date: Fri Jul 24 2015 - 15:32:03 EST


The recursive spinlock implementation trips up sparse and it
complains that these functions have lock imbalances. That isn't
really true though, so add some __acquires() and __releases()
information so that sparse is quiet.

drivers/clk/clk.c:116:22: warning: context imbalance in 'clk_enable_lock' - wrong count at exit
drivers/clk/clk.c:141:9: warning: context imbalance in 'clk_enable_unlock' - unexpected unlock

Signed-off-by: Stephen Boyd <sboyd@xxxxxxxxxxxxxx>
---
drivers/clk/clk.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 67f778bd093b..7bb975747a2c 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -114,12 +114,14 @@ static void clk_prepare_unlock(void)
}

static unsigned long clk_enable_lock(void)
+ __acquires(enable_lock)
{
unsigned long flags;

if (!spin_trylock_irqsave(&enable_lock, flags)) {
if (enable_owner == current) {
enable_refcnt++;
+ __acquire(enable_lock);
return flags;
}
spin_lock_irqsave(&enable_lock, flags);
@@ -132,12 +134,15 @@ static unsigned long clk_enable_lock(void)
}

static void clk_enable_unlock(unsigned long flags)
+ __releases(enable_lock)
{
WARN_ON_ONCE(enable_owner != current);
WARN_ON_ONCE(enable_refcnt == 0);

- if (--enable_refcnt)
+ if (--enable_refcnt) {
+ __release(enable_lock);
return;
+ }
enable_owner = NULL;
spin_unlock_irqrestore(&enable_lock, flags);
}
--
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a Linux Foundation Collaborative Project

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