Re: [PATCH v4 23/25] accel/qda: Add DSP capability query

[Arnd Bergmann]

On Sun, Nov 1, 2026, at 23:21, Ekansh Gupta wrote:

>   *
>   * This structure is used with DRM_IOCTL_QDA_QUERY to query device attributes
> - * based on @query_type.
> + * based on @query_type. @dsp_name and @cap share storage, as only one query
> + * is made per call.
>   */
>  struct drm_qda_query {
>  	__u32 query_type;
> -	__u8 dsp_name[16];
> +	union {
> +		__u8 dsp_name[16];
> +		struct {
> +			__u32 attribute_id;
> +			__u32 capability;
> +		} cap;
> +	};
>  };

I think it would be better to make this separate ioctl commands
instead of a multiplexer for each thing you query. ioctl numbers
are cheap, but complexity is not.

    Arnd