[PATCH] clk: fix clk_get on of_clk_get_by_name return check

[Shawn Guo]

The commit 766e6a4 (clk: add DT clock binding support) plugs device
tree clk lookup of_clk_get_by_name into clk_get, and fall on non-DT
lookup clk_get_sys if DT lookup fails.

The return check on of_clk_get_by_name takes (clk != NULL) as a
successful DT lookup.  But it's not the case.  For any system that
does not define clk lookup in device tree, ERR_PTR(-ENOENT) will be
returned, and consequently, all the client drivers calling clk_get
in their probe functions will fail to probe with error code -ENOENT
returned.

Fix the issue by checking of_clk_get_by_name return with !IS_ERR(clk).

Signed-off-by: Shawn Guo <shawn.guo at linaro.org>
---
 drivers/clk/clkdev.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/clk/clkdev.c b/drivers/clk/clkdev.c
index 20649b3..69085e0 100644
--- a/drivers/clk/clkdev.c
+++ b/drivers/clk/clkdev.c
@@ -157,7 +157,7 @@ struct clk *clk_get(struct device *dev, const char *con_id)
 
 	if (dev) {
 		clk = of_clk_get_by_name(dev->of_node, con_id);
-		if (clk && __clk_get(clk))
+		if (!IS_ERR(clk) && __clk_get(clk))
 			return clk;
 	}
 
-- 
1.7.5.4