於 二，2012-07-31 於 16:41 +0100，Mark Brown 提到：
> On Tue, Jul 31, 2012 at 10:21:56AM +0800, Axel Lin wrote:
> > 於 一，2012-07-30 於 16:33 +0100，Mark Brown 提到：
> > > On Mon, Jul 30, 2012 at 07:47:13AM +0800, Axel Lin wrote:
>
> > > > _notifier_call_chain(rdev,
> > > > REGULATOR_EVENT_VOLTAGE_CHANGE,
> > > > - (void *)best_val);
> > > > + (void *)(uintptr_t)best_val);
>
> > > This also looks problematic, you should never need to cast a pointer to
> > > or from void.
>
> > If I remove the cast to (void *), I got below build warning:
>
> > CC drivers/regulator/core.o
> > drivers/regulator/core.c: In function '_regulator_do_set_voltage':
> > drivers/regulator/core.c:2183:10: warning: passing argument 3 of
> > '_notifier_call_chain' makes pointer from integer without a cast
> > [enabled by default]
> > drivers/regulator/core.c:94:13: note: expected 'void *' but argument is
> > of type 'long unsigned int'
>
> So the above cast probably isn't right... you shouldn't need a double
> cast here.
The issue of original warning is: ( I compile the kernel on x86_64 )
warning: cast to pointer from integer of different size
What this patch does is:
cast best_val to uintptr_t, which is an unsigned integer large enough to
hold a void* pointer.
And then cast it to (void *).
Thus I did (void *)(uintptr_t)best_val.
Regards,
Axel
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