2013-08-22 07:17:56

by Mike Turquette

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Subject: [PATCH] clk: handle NULL struct clk gracefully

At some point changes to clk_set_rate and clk_set_parent introduced a
bug whereby NULL struct clk pointers were treated as an error. This is
in violation of the API in include/linux/clk.h. Reintroduce graceful
handling of NULL clk's by bailing from clk_set_rate and clk_set_parent
with return codes of zero.

Signed-off-by: Mike Turquette <[email protected]>
---
drivers/clk/clk.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index bc02037..7c43762 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -1428,6 +1428,9 @@ int clk_set_rate(struct clk *clk, unsigned long rate)
struct clk *top, *fail_clk;
int ret = 0;

+ if (!clk)
+ return 0;
+
/* prevent racing with updates to the clock topology */
clk_prepare_lock();

@@ -1567,7 +1570,10 @@ int clk_set_parent(struct clk *clk, struct clk *parent)
u8 p_index = 0;
unsigned long p_rate = 0;

- if (!clk || !clk->ops)
+ if (!clk)
+ return 0;
+
+ if (!clk->ops)
return -EINVAL;

/* verify ops for for multi-parent clks */
--
1.8.1.2