Re: [PATCH] mach_omap2: use PTR_RET instead of IS_ERR + PTR_ERR

[Silviu Popescu]

On Wed, Mar 20, 2013 at 8:28 PM, Jon Hunter <jon-hunter@xxxxxx> wrote:
>
> On 03/12/2013 06:05 AM, Russell King - ARM Linux wrote:
>> On Tue, Mar 12, 2013 at 09:58:29AM +0200, Silviu-Mihai Popescu wrote:
>>> This uses PTR_RET instead of IS_ERR and PTR_ERR in order to increase
>>> readability.
>>>
>>> Signed-off-by: Silviu-Mihai Popescu <silviupopescu1990@xxxxxxxxx>
>>> ---
>>>  arch/arm/mach-omap2/devices.c |    4 ++--
>>>  arch/arm/mach-omap2/fb.c      |    5 +----
>>>  arch/arm/mach-omap2/gpmc.c    |    2 +-
>>>  arch/arm/mach-omap2/pmu.c     |    5 +----
>>>  4 files changed, 5 insertions(+), 11 deletions(-)
>>>
>>> diff --git a/arch/arm/mach-omap2/devices.c b/arch/arm/mach-omap2/devices.c
>>> index 1ec7f05..2a0816e 100644
>>> --- a/arch/arm/mach-omap2/devices.c
>>> +++ b/arch/arm/mach-omap2/devices.c
>>> @@ -66,7 +66,7 @@ static int __init omap3_l3_init(void)
>>>
>>>      WARN(IS_ERR(pdev), "could not build omap_device for %s\n", oh_name);
>>>
>>> -    return IS_ERR(pdev) ? PTR_ERR(pdev) : 0;
>>> +    return PTR_RET(pdev);
>>
>> This is incorrect.
>>
>> The return value will be tested for < 0.  Kernel pointers in general are
>> all above 3GB, and so are all "< 0".
>>
>> I'm afraid none of these changes stuff is an improvement - they all
>> introduce bugs.
>
> Sorry I am now not sure I follow you here. Someone just pointed out to
> me that PTR_RET() is defined as ...
>
> static inline int __must_check PTR_RET(const void *ptr)
> {
>         if (IS_ERR(ptr))
>                 return PTR_ERR(ptr);
>         else
>                 return 0;
> }
>
> So the above change appears to be equivalent. Is there something that is
> wrong with the current implementation that needs to be fixed?


As the patch message says, it's just for readability purposes.
I used make coccicheck and it suggested this minor change.

--
Silviu Popescu
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