Re: [PATCH v2 6/6] of/device: Don't NULLify match table in of_match_device() with CONFIG_OF=n

[Arnd Bergmann]

On Sat, Jan 23, 2021 at 4:44 AM Stephen Boyd <swboyd@xxxxxxxxxxxx> wrote:
>
> This effectively reverts 1db73ae39a97 ("of/device: Nullify match table
> in of_match_device() for CONFIG_OF=n") because that commit makes it more
> surprising to users of this API that the arguments may never be
> referenced by any code. This is because the pre-processor will replace
> the argument with NULL and then the match table will be left unreferenced
> by any code but the compiler optimizer doesn't know to drop it. This can
> lead to compilers warning that match tables are unused, when we really
> want to pass the match table to the API but have the compiler see that
> it's all inlined and not used and then drop the match table while
> silencing the warning. We're being too smart here and not giving the
> compiler the chance to do dead code elimination.
>
> Signed-off-by: Stephen Boyd <swboyd@xxxxxxxxxxxx>
> Acked-by: Frank Rowand <frowand.list@xxxxxxxxx>
> Cc: Arnd Bergmann <arnd@xxxxxxxx>
> Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
> Cc: Rob Herring <robh+dt@xxxxxxxxxx>
> Cc: Frank Rowand <frowand.list@xxxxxxxxx>

Reviewed-by: Arnd Bergmann <arnd@xxxxxxxx>