Re: [PATCH 1/1] staging: ks7010: Fix cast to restricted __le16 in ks_wlan_net.c

[Luc Van Oostenryck]

On Sun, Jul 2, 2017 at 10:49 PM, Janusz Lisiecki
<janusz.lisiecki@xxxxxxxxx> wrote:
> W dniu 2017-07-02 o 21:38, Luc Van Oostenryck pisze:
>
>> On Sun, Jul 2, 2017 at 4:27 PM, Janusz Lisiecki
>> <janusz.lisiecki@xxxxxxxxx> wrote:
>>>
>>> This patch fixes the following Sparse warnings in ks_wlan_net.c:
>>> drivers/staging/ks7010/ks_wlan_net.c:1359:24: warning: cast to restricted
>>> __le16
>>> Both sides of assignment are u16 so (as 'ap' is local_ap_t type and
>>> 'capability' member,
>>> have the same as local 'capabilities' type of u16) 'le16_to_cpu' is not
>>> needed
>>
>> It could be that it's ap->capability's type that is wrong (not
>> annotated with __le16).
>> Isn't it?
>>
>> Is ap->capability supposed to hold a little-endian value or a native
>> order value?
>>
>> -- Luc
>
> As I see in ks_hostif.c all assignments to link_ap_info_t->capability threat
> this value as native order (i.e get_ap_information, get_current_ap). As this
> is not a structure which comes from HW we can do the way you suggested.
> Still, as all other places in code threats this as native order value I
> decided to change only one place than many other around to fix Sparse
> warning.

Fine, but then please put this explanation in the commit message.
In others words, be very clear that the change is because ap->capability is in
native order and thus the conversion le16_to_cpu() is wrong and must be removed.

-- Luc