Re: [PATCH 2/4] arch/arm/mach-at91/clock.c: Add missing IS_ERR test

walter harms
2011-01-25T10:33:27Z

Am 24.01.2011 21:09, schrieb Julia Lawall:
> On Mon, 24 Jan 2011, Vasiliy Kulikov wrote:
>
>> On Mon, Jan 24, 2011 at 21:00 +0100, Julia Lawall wrote:
>>> On Tue, 25 Jan 2011, Ryan Mallon wrote:
>>>
>>>> On 01/25/2011 08:55 AM, Julia Lawall wrote:
>>>>> @@ -224,7 +224,7 @@ void __init at91_clock_associate(const char *id, struct device *dev, const char
>>>>> {
>>>>> struct clk *clk = clk_get(NULL, id);
>>>>>
>>>>> - if (!dev || !clk || !IS_ERR(clk_get(dev, func)))
>>>>> + if (!dev || IS_ERR(clk) || !IS_ERR(clk_get(dev, func)))
>>>>> return;
>>>>
>>>> I think we want:
>>>>
>>>> if (!dev || !clk || IS_ERR(clk) || !IS_ERR(clk_get(dev, func)))
>>>> return;
>>>>
>>>> Since it is valid to return a NULL clk, and we don't want to try and
>>>> dereference it if that is the case.
>>>
>>> Looking at the given defintion of clk_get, I can't see how that could
>>> happen:
>>
>> clk_get() is defined per-architecture, sometimes it is NULL only.
>
> In this case there is a definition in the same file, so it doesn't seem
> necessary to worry about possible other ones. Unless there is some goal
> in the future to remove the local one?
>

Would it be more easy to return NULL in the error case of clk_get() instead
of ERR_PTR(-ENOENT) ?

So the default could be return NULL and an architecture depending solution
replacing that.

re,
wh