Re: [PATCH net v3] ice: use proper macro for testing bit

[Jiri Pirko]

Tue, Jun 18, 2024 at 01:11:19PM CEST, poros@xxxxxxxxxx wrote:
>Do not use _test_bit() macro for testing bit. The proper macro for this
>is one without underline.
>
>_test_bit() is what test_bit() was prior to const-optimization. It
>directly calls arch_test_bit(), i.e. the arch-specific implementation
>(or the generic one). It's strictly _internal_ and shouldn't be used
>anywhere outside the actual test_bit() macro.
>
>test_bit() is a wrapper which checks whether the bitmap and the bit
>number are compile-time constants and if so, it calls the optimized
>function which evaluates this call to a compile-time constant as well.
>If either of them is not a compile-time constant, it just calls _test_bit().
>test_bit() is the actual function to use anywhere in the kernel.
>
>IOW, calling _test_bit() avoids potential compile-time optimizations.
>
>The sensors is not a compile-time constant, thus most probably there
>are no object code changes before and after the patch.
>But anyway, we shouldn't call internal wrappers instead of
>the actual API.
>
>Fixes: 4da71a77fc3b ("ice: read internal temperature sensor")
>Acked-by: Ivan Vecera <ivecera@xxxxxxxxxx>
>Reviewed-by: Alexander Lobakin <aleksander.lobakin@xxxxxxxxx>
>Signed-off-by: Petr Oros <poros@xxxxxxxxxx>

Reviewed-by: Jiri Pirko <jiri@xxxxxxxxxx>