On 2/8/19 10:06 AM, Sakari Ailus wrote:
> On Fri, Feb 08, 2019 at 09:49:23AM +0100, Hans Verkuil wrote:
>> The sd argument of this macro can be a more complex expression. Since it
>> is used 5 times in the macro it can be evaluated that many times as well.
>>
>> So assign it to a temp variable in the beginning and use that instead.
>>
>> This also avoids any potential side-effects of evaluating sd.
>>
>> Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
>
> Nice one!
>
> Acked-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
>
> I wonder if this addresses some of the sparse issues related to using a
> macro to come up with sd?
It does solve those as well, in fact :-)
I rejected the omap3/4 patches in favor of this one, which is a much, much
cleaner solution.
Regards,
Hans
>
>> ---
>> diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h
>> index 47af609dc8f1..34da094a3f40 100644
>> --- a/include/media/v4l2-subdev.h
>> +++ b/include/media/v4l2-subdev.h
>> @@ -1093,13 +1093,14 @@ void v4l2_subdev_init(struct v4l2_subdev *sd,
>> */
>> #define v4l2_subdev_call(sd, o, f, args...) \
>> ({ \
>> + struct v4l2_subdev *__sd = (sd); \
>> int __result; \
>> - if (!(sd)) \
>> + if (!__sd) \
>> __result = -ENODEV; \
>> - else if (!((sd)->ops->o && (sd)->ops->o->f)) \
>> + else if (!(__sd->ops->o && __sd->ops->o->f)) \
>> __result = -ENOIOCTLCMD; \
>> else \
>> - __result = (sd)->ops->o->f((sd), ##args); \
>> + __result = __sd->ops->o->f(__sd, ##args); \
>> __result; \
>> })
>>
>
