Re: [PATCH 13/30] net: Don't do pointless kmalloc return value casts in zd1211 driver

[Herbert Xu]

Jesper Juhl <jesper.juhl@xxxxxxxxx> wrote:
> On 30/08/2007, Daniel Drake <dsd@xxxxxxxxxx> wrote:
>> Jesper Juhl wrote:
>> > Since kmalloc() returns a void pointer there is no reason to cast
>> > its return value.
>> > This patch also removes a pointless initialization of a variable.
>>
>> NAK: adds a sparse warning
>> zd_chip.c:116:15: warning: implicit cast to nocast type
>>
> Ok, I must admit I didn't check with sparse since it seemed pointless
> - we usually never cast void pointers to other pointer types,
> specifically because the C language nicely guarantees that the right
> thing will happen without the cast.  Sometimes we have to cast them to
> integer types, su sure we need the cast there.   But what on earth
> makes a "zd_addr_t *" so special that we have to explicitly cast a
> "void *" to that type?
> 
> I see it's defined as
>  typedef u32 __nocast zd_addr_t;
> in drivers/net/wireless/zd1211rw/zd_types.h , but why the __nocast ?

Nevermind the __nocast, this looks like a bug in sparse.  Just
because a base type is __nocast, sparse shouldn't infer that a
pointer to it should also be __nocast.

Cheers,
-- 
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