[PATCH 3.16 090/133] MIPS: Loongson 2F: allow NULL clock for clk_get_rate

[Ben Hutchings]

3.16.51-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Jonas Gorski <jonas.gorski@xxxxxxxxx>

commit 386787b1fcab2dd3d16ca3f46729aaafdef306e3 upstream.

Make the behaviour of clk_get_rate consistent with common clk's
clk_get_rate by accepting NULL clocks as parameter, as some device
drivers rely on this.

Make the behaviour of clk_get_rate consistent with common clk's
clk_get_rate by accepting NULL clocks as parameter. Some device
drivers rely on this, and will cause an OOPS otherwise.

Fixes: f8ede0f700f5 ("MIPS: Loongson 2F: Add CPU frequency scaling support")
Reported-by: Mathias Kresin <dev@xxxxxxxxx>
Signed-off-by: Jonas Gorski <jonas.gorski@xxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Patchwork: https://patchwork.linux-mips.org/patch/16777/
Signed-off-by: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
[bwh: Backported to 3.16: adjust filename]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 arch/mips/loongson/lemote-2f/clock.c | 3 +++
 1 file changed, 3 insertions(+)

--- a/arch/mips/loongson/lemote-2f/clock.c
+++ b/arch/mips/loongson/lemote-2f/clock.c
@@ -80,6 +80,9 @@ EXPORT_SYMBOL(clk_disable);
 
 unsigned long clk_get_rate(struct clk *clk)
 {
+	if (!clk)
+		return 0;
+
 	return (unsigned long)clk->rate;
 }
 EXPORT_SYMBOL(clk_get_rate);