Re: [PATCH v5 5/6] media: subdev: add v4l2_subdev_call_state_active()

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Hi Tomi,

Thank you for the patch.

On Tue, Mar 01, 2022 at 12:55:47PM +0200, Tomi Valkeinen wrote:
> Add v4l2_subdev_call_state_active() macro to help calling subdev ops
> that take a subdev state as a parameter. Normally the v4l2 framework
> will lock and pass the correct subdev state to the subdev ops, but there
> are legacy situations where this is not the case (e.g. non-MC video
> device driver calling set_fmt in a source subdev).
> 
> As this macro is only needed for legacy use cases, the macro is added in
> a new header file, v4l2-subdev-legacy.h.
> 
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@xxxxxxxxxxxxxxxx>
> ---
>  include/media/v4l2-subdev-legacy.h | 42 ++++++++++++++++++++++++++++++
>  1 file changed, 42 insertions(+)
>  create mode 100644 include/media/v4l2-subdev-legacy.h
> 
> diff --git a/include/media/v4l2-subdev-legacy.h b/include/media/v4l2-subdev-legacy.h
> new file mode 100644
> index 000000000000..6a61e579b629
> --- /dev/null
> +++ b/include/media/v4l2-subdev-legacy.h
> @@ -0,0 +1,42 @@
> +/* SPDX-License-Identifier: GPL-2.0-or-later */
> +/*
> + *  V4L2 sub-device legacy support header.
> + *
> + *  Copyright (C) 2022  Tomi Valkeinen <tomi.valkeinen@xxxxxxxxxxxxxxxx>
> + */
> +
> +#ifndef _V4L2_SUBDEV_LEGACY_H
> +#define _V4L2_SUBDEV_LEGACY_H
> +
> +/**
> + * v4l2_subdev_call_state_active - call an operation of a v4l2_subdev which
> + *				   takes state as a parameter, passing the
> + *				   subdev its active state.
> + *
> + * @sd: pointer to the &struct v4l2_subdev
> + * @o: name of the element at &struct v4l2_subdev_ops that contains @f.
> + *     Each element there groups a set of callbacks functions.
> + * @f: callback function to be called.
> + *     The callback functions are defined in groups, according to
> + *     each element at &struct v4l2_subdev_ops.
> + * @args: arguments for @f.
> + *
> + * This is similar to v4l2_subdev_call(), except that this version can only be
> + * used for ops that take a subdev state as a parameter. The macro will get the
> + * active state and lock it before calling the op, and unlock it after the

s/active state and/active state,/

> + * call.
> + */
> +#define v4l2_subdev_call_state_active(sd, o, f, args...)		\
> +	({								\
> +		int __result;						\
> +		struct v4l2_subdev_state *state;			\
> +		state = v4l2_subdev_get_active_state(sd);		\
> +		if (state)						\
> +			v4l2_subdev_lock_state(state);			\
> +		__result = v4l2_subdev_call(sd, o, f, state, ##args);	\
> +		if (state)						\
> +			v4l2_subdev_unlock_state(state);		\
> +		__result;						\
> +	})
> +
> +#endif

I think

#endif /* _V4L2_SUBDEV_LEGACY_H */

is the usual pattern. Apart from that,

Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>

-- 
Regards,

Laurent Pinchart



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