2015-12-03 02:20:18

by Masahiro Yamada

Subject: [PATCH v3] 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 <[email protected]>
---

Changes in v3:
- Choose the least invasive way

Changes in v2:
- Rephrase the git-log

drivers/clk/clk.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 88a723b..1d95033 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,
--
1.9.1

2015-12-03 06:35:11

by Stephen Boyd

Subject: Re: [PATCH v3] clk: let of_clk_get_parent_name() fail for invalid clock-indices

On 12/03, Masahiro Yamada wrote:
> 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 <[email protected]>
> ---

Applied to clk-next

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