Re: [PATCH] media: mali-c55: add padding to mali_c55_params_ccm structure

[Jacopo Mondi <jacopo.mondi@ideasonboard.com>]

Hi Arnd

On Tue, Sep 15, 2026 at 10:24:48PM +0200, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
>
> The newly added structure has extra padding on the on
> some architectures, which triggers a pedantic uapi check:
>
> ./usr/include/linux/media/arm/mali-c55-config.h:807:1: error: padding struct size to alignment boundary with 2 bytes [-Werror=padded]
>
> Add explicit padding here to avoid risking information leaks
> and incompatibilities between architectures.
>
> Fixes: bb401df68c06 ("media: mali-c55: Add support for CCM")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

The documentation of the newly added field is missing, triggering a
warning when building the documentation

https://gitlab.freedesktop.org/linux-media/users/patchwork/-/jobs/110343884
WARNING: ./include/uapi/linux/media/arm/mali-c55-config.h:803 struct member '__pad' not described in 'mali_c55_params_ccm'

I am about to send a PR collecting all mali-related changes, I can add

 * @__pad:	Padding bytes

To the documentation of struct mali_c55_params_ccm.

> ---
>  include/uapi/linux/media/arm/mali-c55-config.h | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/include/uapi/linux/media/arm/mali-c55-config.h b/include/uapi/linux/media/arm/mali-c55-config.h
> index 84d8f3901405..9c922290e035 100644
> --- a/include/uapi/linux/media/arm/mali-c55-config.h
> +++ b/include/uapi/linux/media/arm/mali-c55-config.h
> @@ -804,6 +804,7 @@ struct mali_c55_params_ccm {
>  	__u16 coeffs[3][3];
>  	__u16 gains[3];
>  	__u16 offs[3];
> +	__u16 __pad;
>  };
>
>  /**
> --
> 2.53.0
>
>