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SubjectRe: [PATCH 10/10] of/device: Don't NULLify match table in of_match_device() with CONFIG_OF=n
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On 10/04/2019 16:43, Stephen Boyd 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.
>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Geert Uytterhoeven <geert@linux-m68k.org>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: Frank Rowand <frowand.list@gmail.com>
> Signed-off-by: Stephen Boyd <swboyd@chromium.org>
> ---
>
> Please ack or pick for immediate merge so the last patch can be merged.
>
> include/linux/of_device.h | 4 +---
> 1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/include/linux/of_device.h b/include/linux/of_device.h
> index 8d31e39dd564..3f8ca55bc693 100644
> --- a/include/linux/of_device.h
> +++ b/include/linux/of_device.h
> @@ -93,13 +93,11 @@ static inline int of_device_uevent_modalias(struct device *dev,
>
> static inline void of_device_node_put(struct device *dev) { }
>
> -static inline const struct of_device_id *__of_match_device(
> +static inline const struct of_device_id *of_match_device(
> const struct of_device_id *matches, const struct device *dev)
> {
> return NULL;
> }
> -#define of_match_device(matches, dev) \
> - __of_match_device(of_match_ptr(matches), (dev))
>
> static inline struct device_node *of_cpu_device_node_get(int cpu)
> {
>


Acked-by: Frank Rowand <frowand.list@gmail.com>

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