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

From: Jeremy Kerr
Date: Mon Feb 07 2011 - 01:09:06 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, these warnings should cover
most situations.

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 51dbd33..2369959 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -35,6 +35,8 @@ void clk_unprepare(struct clk *clk)
if (!clk->ops->unprepare)
return;

+ WARN_ON(clk->enable_count);
+
mutex_lock(&clk->prepare_lock);
if (--clk->prepare_count == 0)
clk->ops->unprepare(clk);
@@ -50,6 +52,8 @@ int clk_enable(struct clk *clk)
if (!clk->ops->enable)
return 0;

+ WARN_ON(clk->ops->prepare && clk->prepare_count);
+
spin_lock(&clk->enable_lock);
if (!clk->enable_count)
ret = clk->ops->enable(clk);
--
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