[RFC,PATCH 3/3] clk: add warnings for incorrect enable/prepare semantics

From: Jeremy Kerr
Date: Wed Feb 09 2011 - 01:41:53 EST


This change adds warnings to check for:

1) enabling a clock that hasn't been prepared; and

2) unpreparing a clock that is still enabled

While the correctness can't be guaranteed, the warnings should cover
most situations, and won't indicate false positives.

Signed-off-by: Jeremy Kerr <jeremy.kerr@xxxxxxxxxxxxx>

---
drivers/clk/clk.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index bbbdb0d..8c96623 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -29,6 +29,8 @@ EXPORT_SYMBOL_GPL(clk_prepare);

void clk_unprepare(struct clk *clk)
{
+ WARN_ON(clk->enable_count != 0);
+
mutex_lock(&clk->prepare_lock);

WARN_ON(clk->prepare_count == 0);
@@ -45,6 +47,8 @@ int clk_enable(struct clk *clk)
unsigned long flags;
int ret = 0;

+ WARN_ON(clk->prepare_count == 0);
+
spin_lock_irqsave(&clk->enable_lock, flags);
if (clk->enable_count == 0 && clk->ops->enable)
ret = clk->ops->enable(clk);
--
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