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From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To: Sakari Ailus <sakari.ailus@linux.intel.com>
Cc: linux-media@vger.kernel.org, hverkuil@xs4all.nl,
	tomi.valkeinen@ideasonboard.com, jacopo.mondi@ideasonboard.com,
	bingbu.cao@intel.com, hongju.wang@intel.com,
	Alain Volmat <alain.volmat@foss.st.com>
Subject: Re: [PATCH v4 5/9] media: v4l: subdev: Make stream argument optional in state access functions
Date: Thu, 26 Oct 2023 16:49:04 +0300	[thread overview]
Message-ID: <20231026134904.GC26306@pendragon.ideasonboard.com> (raw)
In-Reply-To: <20231026070329.948847-6-sakari.ailus@linux.intel.com>

On Thu, Oct 26, 2023 at 10:03:25AM +0300, Sakari Ailus wrote:
> The sub-device state access functions take three arguments: sub-device
> state, pad and stream. The stream is not relevant for the majority of
> drivers and having to specify 0 for the stream is considered a nuisance.
> 
> Provide a two-argument macros for these state access functions to cover
> the needs of stream-unaware users.
> 
> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> ---
>  drivers/media/v4l2-core/v4l2-subdev.c | 18 +++++-----
>  include/media/v4l2-subdev.h           | 48 ++++++++++++++++++++++-----
>  2 files changed, 48 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
> index 2a615836c1d4..9d4ff9b4fcec 100644
> --- a/drivers/media/v4l2-core/v4l2-subdev.c
> +++ b/drivers/media/v4l2-core/v4l2-subdev.c
> @@ -1671,8 +1671,8 @@ int v4l2_subdev_set_routing_with_fmt(struct v4l2_subdev *sd,
>  EXPORT_SYMBOL_GPL(v4l2_subdev_set_routing_with_fmt);
>  
>  struct v4l2_mbus_framefmt *
> -v4l2_subdev_state_get_format(struct v4l2_subdev_state *state, unsigned int pad,
> -			     u32 stream)
> +__v4l2_subdev_state_get_format_stream(struct v4l2_subdev_state *state,
> +				      unsigned int pad, u32 stream)
>  {
>  	struct v4l2_subdev_stream_configs *stream_configs;
>  	unsigned int i;
> @@ -1706,11 +1706,11 @@ v4l2_subdev_state_get_format(struct v4l2_subdev_state *state, unsigned int pad,
>  
>  	return NULL;
>  }
> -EXPORT_SYMBOL_GPL(v4l2_subdev_state_get_format);
> +EXPORT_SYMBOL_GPL(__v4l2_subdev_state_get_format_stream);
>  
>  struct v4l2_rect *
> -v4l2_subdev_state_get_crop(struct v4l2_subdev_state *state, unsigned int pad,
> -			   u32 stream)
> +__v4l2_subdev_state_get_crop_stream(struct v4l2_subdev_state *state,
> +				    unsigned int pad, u32 stream)
>  {
>  	struct v4l2_subdev_stream_configs *stream_configs;
>  	unsigned int i;
> @@ -1744,11 +1744,11 @@ v4l2_subdev_state_get_crop(struct v4l2_subdev_state *state, unsigned int pad,
>  
>  	return NULL;
>  }
> -EXPORT_SYMBOL_GPL(v4l2_subdev_state_get_crop);
> +EXPORT_SYMBOL_GPL(__v4l2_subdev_state_get_crop_stream);
>  
>  struct v4l2_rect *
> -v4l2_subdev_state_get_compose(struct v4l2_subdev_state *state, unsigned int pad,
> -			      u32 stream)
> +__v4l2_subdev_state_get_compose_stream(struct v4l2_subdev_state *state,
> +				       unsigned int pad, u32 stream)
>  {
>  	struct v4l2_subdev_stream_configs *stream_configs;
>  	unsigned int i;
> @@ -1782,7 +1782,7 @@ v4l2_subdev_state_get_compose(struct v4l2_subdev_state *state, unsigned int pad,
>  
>  	return NULL;
>  }
> -EXPORT_SYMBOL_GPL(v4l2_subdev_state_get_compose);
> +EXPORT_SYMBOL_GPL(__v4l2_subdev_state_get_compose_stream);
>  
>  int v4l2_subdev_routing_find_opposite_end(const struct v4l2_subdev_krouting *routing,
>  					  u32 pad, u32 stream, u32 *other_pad,
> diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h
> index 71cb35133b4a..ebb3373b431a 100644
> --- a/include/media/v4l2-subdev.h
> +++ b/include/media/v4l2-subdev.h
> @@ -1545,7 +1545,7 @@ int v4l2_subdev_set_routing_with_fmt(struct v4l2_subdev *sd,
>   * v4l2_subdev_state_get_format() - Get pointer to a stream format
>   * @state: subdevice state
>   * @pad: pad id
> - * @stream: stream id
> + * @...: stream id (optional argument)
>   *
>   * This returns a pointer to &struct v4l2_mbus_framefmt for the given pad +
>   * stream in the subdev state.
> @@ -1553,15 +1553,31 @@ int v4l2_subdev_set_routing_with_fmt(struct v4l2_subdev *sd,
>   * For stream-unaware drivers the format for the corresponding pad is returned.
>   * If the pad does not exist, NULL is returned.
>   */
> +/*
> + * Wrap v4l2_subdev_state_get_format(), allowing the function to be called with
> + * two or three arguments. The purpose of the __v4l2_subdev_state_get_format()
> + * macro below is to come up with the name of the function or macro to call,
> + * using the last two arguments (_stream and _pad). The selected function or
> + * macro is then called using the arguments specified by the caller. A similar
> + * arrangement is used for v4l2_subdev_state_crop() and
> + * v4l2_subdev_state_compose() below.
> + */
> +#define v4l2_subdev_state_get_format(...)				\
> +	__v4l2_subdev_state_get_format(__VA_ARGS__,			\
> +				       _stream, _pad)(__VA_ARGS__)
> +#define __v4l2_subdev_state_get_format(_1, _2, _3, ARG, ...)	\

How about renaming this macro to __v4l2_subdev_state_get_format_name ...

> +	__v4l2_subdev_state_get_format ## ARG
> +#define __v4l2_subdev_state_get_format_pad(state, pad)		\
> +	__v4l2_subdev_state_get_format_stream(state, pad, 0)
>  struct v4l2_mbus_framefmt *
> -v4l2_subdev_state_get_format(struct v4l2_subdev_state *state, unsigned int pad,
> -			     u32 stream);
> +__v4l2_subdev_state_get_format_stream(struct v4l2_subdev_state *state,
> +				      unsigned int pad, u32 stream);

... and this function to __v4l2_subdev_state_get_format() ? That way the
macro used by drivers and the backend function will have the same name,
with a __ prefix for the function. I think it would be a bit cleaner.
Same below.

But now that I've written that, I realize you would need an additional
__v4l2_subdev_state_get_format_stream() macro. I'll let you decide if
you think that's cleaner or not.


You could also take it one step forward, and avoid three copies of the
same name selection macro:

#define __v4l2_subdev_state_get_macro(name, _1, _2, _3, ARG, ...)	\
	__v4l2_subdev_state_get_ ## name ## ARG

#define v4l2_subdev_state_get_format(...)				\
	__v4l2_subdev_state_get_macro(format, __VA_ARGS__,		\
				      _stream, _pad)(__VA_ARGS__)
#define __v4l2_subdev_state_get_format_pad(state, pad)			\
	__v4l2_subdev_state_get_format(state, pad, 0)
#define __v4l2_subdev_state_get_format_stream(state, pad, stream)	\
	__v4l2_subdev_state_get_format(state, pad, stream)

struct v4l2_mbus_framefmt *
__v4l2_subdev_state_get_format(struct v4l2_subdev_state *state,
			       unsigned int pad, u32 stream);

This can be done regardless of whether or not we want to drop the
_stream suffix from the backend functions.

>  
>  /**
>   * v4l2_subdev_state_get_crop() - Get pointer to a stream crop rectangle
>   * @state: subdevice state
>   * @pad: pad id
> - * @stream: stream id
> + * @...: stream id (optional argument)
>   *
>   * This returns a pointer to crop rectangle for the given pad + stream in the
>   * subdev state.
> @@ -1569,15 +1585,22 @@ v4l2_subdev_state_get_format(struct v4l2_subdev_state *state, unsigned int pad,
>   * For stream-unaware drivers the crop rectangle for the corresponding pad is
>   * returned. If the pad does not exist, NULL is returned.
>   */
> +#define v4l2_subdev_state_get_crop(...)					\
> +	__v4l2_subdev_state_get_crop(__VA_ARGS__,			\
> +				     _stream, _pad)(__VA_ARGS__)
> +#define __v4l2_subdev_state_get_crop(_1, _2, _3, ARG, ...)	\
> +	__v4l2_subdev_state_get_crop ## ARG
> +#define __v4l2_subdev_state_get_crop_pad(state, pad)		\
> +	__v4l2_subdev_state_get_crop_stream(state, pad, 0)
>  struct v4l2_rect *
> -v4l2_subdev_state_get_crop(struct v4l2_subdev_state *state, unsigned int pad,
> -			   u32 stream);
> +__v4l2_subdev_state_get_crop_stream(struct v4l2_subdev_state *state,
> +				    unsigned int pad, u32 stream);
>  
>  /**
>   * v4l2_subdev_state_get_compose() - Get pointer to a stream compose rectangle
>   * @state: subdevice state
>   * @pad: pad id
> - * @stream: stream id
> + * @...: stream id (optional argument)
>   *
>   * This returns a pointer to compose rectangle for the given pad + stream in the
>   * subdev state.
> @@ -1585,9 +1608,16 @@ v4l2_subdev_state_get_crop(struct v4l2_subdev_state *state, unsigned int pad,
>   * For stream-unaware drivers the compose rectangle for the corresponding pad is
>   * returned. If the pad does not exist, NULL is returned.
>   */
> +#define v4l2_subdev_state_get_compose(...)				\
> +	__v4l2_subdev_state_get_compose(__VA_ARGS__,		\
> +					_stream, _pad)(__VA_ARGS__)
> +#define __v4l2_subdev_state_get_compose(_1, _2, _3, ARG, ...)	\
> +	__v4l2_subdev_state_get_compose ## ARG
> +#define __v4l2_subdev_state_get_compose_pad(state, pad)		\
> +	__v4l2_subdev_state_get_compose_stream(state, pad, 0)
>  struct v4l2_rect *
> -v4l2_subdev_state_get_compose(struct v4l2_subdev_state *state, unsigned int pad,
> -			      u32 stream);
> +__v4l2_subdev_state_get_compose_stream(struct v4l2_subdev_state *state,
> +				       unsigned int pad, u32 stream);
>  
>  /**
>   * v4l2_subdev_routing_find_opposite_end() - Find the opposite stream

-- 
Regards,

Laurent Pinchart

  reply	other threads:[~2023-10-26 13:49 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-10-26  7:03 [PATCH v4 0/9] Unify sub-device state access functions Sakari Ailus
2023-10-26  7:03 ` [PATCH v4 1/9] media: v4l: subdev: Store the sub-device in the sub-device state Sakari Ailus
2023-10-26  7:03 ` [PATCH v4 2/9] media: v4l: subdev: Also return pads array information on stream functions Sakari Ailus
2023-10-26  7:11   ` Hans Verkuil
2023-10-26  7:39     ` Sakari Ailus
2023-10-26  7:03 ` [PATCH v4 3/9] media: v4l: subdev: Rename sub-device state information access functions Sakari Ailus
2023-10-26  7:26   ` Hans Verkuil
2023-10-26  8:25     ` Sakari Ailus
2023-10-26  9:51       ` Laurent Pinchart
2023-10-26 10:10         ` Sakari Ailus
2023-10-26 13:40           ` Laurent Pinchart
2023-10-26  7:03 ` [PATCH v4 4/9] media: v4l: subdev: v4l2_subdev_state_get_format always returns format now Sakari Ailus
2023-10-26  7:03 ` [PATCH v4 5/9] media: v4l: subdev: Make stream argument optional in state access functions Sakari Ailus
2023-10-26 13:49   ` Laurent Pinchart [this message]
2023-10-27  9:06     ` Sakari Ailus
2023-10-27  9:10       ` Laurent Pinchart
2023-10-27  9:12         ` Sakari Ailus
2023-10-27  9:14           ` Laurent Pinchart
2023-10-27  9:21             ` Sakari Ailus
2023-10-26  7:03 ` [PATCH v4 6/9] media: v4l: subdev: Switch to stream-aware state functions Sakari Ailus
2023-10-26  7:03 ` [PATCH v4 7/9] media: v4l: subdev: Remove stream-unaware sub-device state access Sakari Ailus
2023-10-26 13:54   ` Laurent Pinchart
2023-10-26  7:03 ` [PATCH v4 8/9] media: v4l: subdev: Return NULL from pad access functions on error Sakari Ailus
2023-10-26  7:35   ` Hans Verkuil
2023-10-26  7:43     ` Sakari Ailus
2023-10-26 13:55   ` Laurent Pinchart
2023-10-26  7:03 ` [PATCH v4 9/9] media: v4l: subdev: Warn on stream when accessing stream-unaware data Sakari Ailus
2023-10-26  7:36   ` Hans Verkuil
2023-10-26  7:40     ` Sakari Ailus
2023-10-26 14:20       ` Laurent Pinchart
2023-10-26 17:50         ` Sakari Ailus
2023-10-26 18:09           ` Laurent Pinchart

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