From: Masahiro Yamada <yamada.masahiro@socionext.com>
Date: Thu, 3 Dec 2015 02:20:35 +0000 (+0900)
Subject: clk: let of_clk_get_parent_name() fail for invalid clock-indices
X-Git-Tag: v4.14-rc1~4001^2~14^2~5
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=8da411cc1964c5d6a0a0f94c7bbf8693c9673a87;p=platform%2Fkernel%2Flinux-rpi.git

clk: let of_clk_get_parent_name() fail for invalid clock-indices

Currently, of_clk_get_parent_name() returns a wrong parent clock name
when "clock-indices" property exists and the target index is not
found in the property.  In this case, NULL should be returned.

For example,

        oscillator {
                compatible = "myclocktype";
                #clock-cells = <1>;
                clock-indices = <1>, <3>;
                clock-output-names = "clka", "clkb";
        };

        consumer {
                compatible = "myclockconsumer";
                clocks = <&oscillator 0>, <&oscillator 1>;
        };

Currently, of_clk_get_parent_name(consumer_np, 0) returns "clka"
(and of_clk_get_parent_name(consumer_np, 1) also returns "clka",
this is correct).   Because the "clock-indices" in the clock parent
does not contain <0>, of_clk_get_parent_name(consumer_np, 0) should
return NULL.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
---

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index a66efc9..9352a13 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -3079,6 +3079,9 @@ const char *of_clk_get_parent_name(struct device_node *np, int index)
 		}
 		count++;
 	}
+	/* We went off the end of 'clock-indices' without finding it */
+	if (prop && !vp)
+		return NULL;
 
 	if (of_property_read_string_index(clkspec.np, "clock-output-names",
 					  index,