| Message ID | 20231023174408.803874-6-sakari.ailus@linux.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Unify sub-device state access functions | expand |
Hi Sakari, Thank you for the patch. On Mon, Oct 23, 2023 at 08:44:05PM +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> > --- > drivers/media/v4l2-core/v4l2-subdev.c | 18 ++++++------- > include/media/v4l2-subdev.h | 39 ++++++++++++++++++++------- > 2 files changed, 39 insertions(+), 18 deletions(-) > > diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c > index f0f0af48730f..e35226587244 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(struct v4l2_subdev_state *state, > + unsigned int pad, u32 stream) > { > struct v4l2_subdev_stream_configs *stream_configs; > unsigned int i; > @@ -1702,11 +1702,11 @@ 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); > > struct v4l2_rect * > -v4l2_subdev_state_get_crop(struct v4l2_subdev_state *state, unsigned int pad, > - u32 stream) > +__v4l2_subdev_state_get_crop(struct v4l2_subdev_state *state, unsigned int pad, > + u32 stream) > { > struct v4l2_subdev_stream_configs *stream_configs; > unsigned int i; > @@ -1736,11 +1736,11 @@ 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); > > struct v4l2_rect * > -v4l2_subdev_state_get_compose(struct v4l2_subdev_state *state, unsigned int pad, > - u32 stream) > +__v4l2_subdev_state_get_compose(struct v4l2_subdev_state *state, > + unsigned int pad, u32 stream) > { > struct v4l2_subdev_stream_configs *stream_configs; > unsigned int i; > @@ -1770,7 +1770,7 @@ 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); > > 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..12eb0fe746d7 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) Not great, but I suppose we can't do better :-S Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > * > * This returns a pointer to &struct v4l2_mbus_framefmt for the given pad + > * stream in the subdev state. > @@ -1553,15 +1553,22 @@ 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. > */ > +#define v4l2_subdev_state_get_format(state, pad, ...) \ > + __v4l2_subdev_state_get_format_ ## __VA_OPT__(stream) \ > + (state, pad __VA_OPT__(,) __VA_ARGS__) > +#define __v4l2_subdev_state_get_format_(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); > +__v4l2_subdev_state_get_format(struct v4l2_subdev_state *state, > + unsigned int pad, u32 stream); > > /** > * 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 +1576,22 @@ 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(state, pad, ...) \ > + __v4l2_subdev_state_get_crop_ ## __VA_OPT__(stream) \ > + (state, pad __VA_OPT__(,) __VA_ARGS__) > +#define __v4l2_subdev_state_get_crop_(state, pad) \ > + __v4l2_subdev_state_get_crop(state, pad, 0) > +#define __v4l2_subdev_state_get_crop_stream(state, pad, stream) \ > + __v4l2_subdev_state_get_crop(state, pad, stream) > struct v4l2_rect * > -v4l2_subdev_state_get_crop(struct v4l2_subdev_state *state, unsigned int pad, > - u32 stream); > +__v4l2_subdev_state_get_crop(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 +1599,16 @@ 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(state, pad, ...) \ > + __v4l2_subdev_state_get_compose_ ## __VA_OPT__(stream) \ > + (state, pad __VA_OPT__(,) __VA_ARGS__) > +#define __v4l2_subdev_state_get_compose_(state, pad) \ > + __v4l2_subdev_state_get_compose(state, pad, 0) > +#define __v4l2_subdev_state_get_compose_stream(state, pad, stream) \ > + __v4l2_subdev_state_get_compose(state, pad, stream) > struct v4l2_rect * > -v4l2_subdev_state_get_compose(struct v4l2_subdev_state *state, unsigned int pad, > - u32 stream); > +__v4l2_subdev_state_get_compose(struct v4l2_subdev_state *state, > + unsigned int pad, u32 stream); > > /** > * v4l2_subdev_routing_find_opposite_end() - Find the opposite stream
On 23/10/2023 19:44, 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> > --- > drivers/media/v4l2-core/v4l2-subdev.c | 18 ++++++------- > include/media/v4l2-subdev.h | 39 ++++++++++++++++++++------- > 2 files changed, 39 insertions(+), 18 deletions(-) > > diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c > index f0f0af48730f..e35226587244 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(struct v4l2_subdev_state *state, > + unsigned int pad, u32 stream) > { > struct v4l2_subdev_stream_configs *stream_configs; > unsigned int i; > @@ -1702,11 +1702,11 @@ 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); > > struct v4l2_rect * > -v4l2_subdev_state_get_crop(struct v4l2_subdev_state *state, unsigned int pad, > - u32 stream) > +__v4l2_subdev_state_get_crop(struct v4l2_subdev_state *state, unsigned int pad, > + u32 stream) > { > struct v4l2_subdev_stream_configs *stream_configs; > unsigned int i; > @@ -1736,11 +1736,11 @@ 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); > > struct v4l2_rect * > -v4l2_subdev_state_get_compose(struct v4l2_subdev_state *state, unsigned int pad, > - u32 stream) > +__v4l2_subdev_state_get_compose(struct v4l2_subdev_state *state, > + unsigned int pad, u32 stream) > { > struct v4l2_subdev_stream_configs *stream_configs; > unsigned int i; > @@ -1770,7 +1770,7 @@ 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); > > 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..12eb0fe746d7 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 +1553,22 @@ 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. > */ > +#define v4l2_subdev_state_get_format(state, pad, ...) \ > + __v4l2_subdev_state_get_format_ ## __VA_OPT__(stream) \ > + (state, pad __VA_OPT__(,) __VA_ARGS__) > +#define __v4l2_subdev_state_get_format_(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) Hmm, 'git grep __VA_OPT__' finds no use of this in the kernel. Are you sure this is safe to use? Does clang support it? Do all gcc versions that the kernel support implement it? A 10+ for creativity, but I'm a bit concerned about it. And if there are only a few drivers that need to give a specific stream, wouldn't it be easier to just have a v4l2_subdev_state_get_format_stream function and a static inline v4l2_subdev_state_get_format() that just calls the _stream version with 0? Regards, Hans > struct v4l2_mbus_framefmt * > -v4l2_subdev_state_get_format(struct v4l2_subdev_state *state, unsigned int pad, > - u32 stream); > +__v4l2_subdev_state_get_format(struct v4l2_subdev_state *state, > + unsigned int pad, u32 stream); > > /** > * 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 +1576,22 @@ 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(state, pad, ...) \ > + __v4l2_subdev_state_get_crop_ ## __VA_OPT__(stream) \ > + (state, pad __VA_OPT__(,) __VA_ARGS__) > +#define __v4l2_subdev_state_get_crop_(state, pad) \ > + __v4l2_subdev_state_get_crop(state, pad, 0) > +#define __v4l2_subdev_state_get_crop_stream(state, pad, stream) \ > + __v4l2_subdev_state_get_crop(state, pad, stream) > struct v4l2_rect * > -v4l2_subdev_state_get_crop(struct v4l2_subdev_state *state, unsigned int pad, > - u32 stream); > +__v4l2_subdev_state_get_crop(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 +1599,16 @@ 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(state, pad, ...) \ > + __v4l2_subdev_state_get_compose_ ## __VA_OPT__(stream) \ > + (state, pad __VA_OPT__(,) __VA_ARGS__) > +#define __v4l2_subdev_state_get_compose_(state, pad) \ > + __v4l2_subdev_state_get_compose(state, pad, 0) > +#define __v4l2_subdev_state_get_compose_stream(state, pad, stream) \ > + __v4l2_subdev_state_get_compose(state, pad, stream) > struct v4l2_rect * > -v4l2_subdev_state_get_compose(struct v4l2_subdev_state *state, unsigned int pad, > - u32 stream); > +__v4l2_subdev_state_get_compose(struct v4l2_subdev_state *state, > + unsigned int pad, u32 stream); > > /** > * v4l2_subdev_routing_find_opposite_end() - Find the opposite stream
Hi Hans, Thank you for the review. On Wed, Oct 25, 2023 at 11:53:35AM +0200, Hans Verkuil wrote: > On 23/10/2023 19:44, 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> > > --- > > drivers/media/v4l2-core/v4l2-subdev.c | 18 ++++++------- > > include/media/v4l2-subdev.h | 39 ++++++++++++++++++++------- > > 2 files changed, 39 insertions(+), 18 deletions(-) > > > > diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c > > index f0f0af48730f..e35226587244 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(struct v4l2_subdev_state *state, > > + unsigned int pad, u32 stream) > > { > > struct v4l2_subdev_stream_configs *stream_configs; > > unsigned int i; > > @@ -1702,11 +1702,11 @@ 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); > > > > struct v4l2_rect * > > -v4l2_subdev_state_get_crop(struct v4l2_subdev_state *state, unsigned int pad, > > - u32 stream) > > +__v4l2_subdev_state_get_crop(struct v4l2_subdev_state *state, unsigned int pad, > > + u32 stream) > > { > > struct v4l2_subdev_stream_configs *stream_configs; > > unsigned int i; > > @@ -1736,11 +1736,11 @@ 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); > > > > struct v4l2_rect * > > -v4l2_subdev_state_get_compose(struct v4l2_subdev_state *state, unsigned int pad, > > - u32 stream) > > +__v4l2_subdev_state_get_compose(struct v4l2_subdev_state *state, > > + unsigned int pad, u32 stream) > > { > > struct v4l2_subdev_stream_configs *stream_configs; > > unsigned int i; > > @@ -1770,7 +1770,7 @@ 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); > > > > 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..12eb0fe746d7 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 +1553,22 @@ 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. > > */ > > +#define v4l2_subdev_state_get_format(state, pad, ...) \ > > + __v4l2_subdev_state_get_format_ ## __VA_OPT__(stream) \ > > + (state, pad __VA_OPT__(,) __VA_ARGS__) > > +#define __v4l2_subdev_state_get_format_(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) > > Hmm, 'git grep __VA_OPT__' finds no use of this in the kernel. Are you sure this > is safe to use? Does clang support it? Do all gcc versions that the kernel support > implement it? > > A 10+ for creativity, but I'm a bit concerned about it. :-) I noticed the problem, too, as the lkp bot failed compiling this on GCC 7.5. Indeed only GCC 8 supports __VA_OPT__ but the oldest GCC version supported for kernel compilation is 7.1. So __VA_OPT__ isn't... an option. I thought this could be done using variable arguments, making most error handling take place at runtime (for GCC versions not supporting __VA_OPT__), but then Laurent figured this can be done with just __VA_ARGS__ which is part of C99. The code would look like this, which is only slightly less understandable than with __VA_OPT__: #define v4l2_subdev_state_get_format(...) \ __v4l2_subdev_state_get_format_var(__VA_ARGS__, , _2)(__VA_ARGS__) #define __v4l2_subdev_state_get_format_var(_1, _2, _3, NUM, ...) \ __v4l2_subdev_state_get_format ## NUM #define __v4l2_subdev_state_get_format_2(state, pad) \ __v4l2_subdev_state_get_format(state, pad, 0) struct v4l2_mbus_framefmt * __v4l2_subdev_state_get_format(struct v4l2_subdev_state *state, unsigned int pad, u32 stream); > > And if there are only a few drivers that need to give a specific stream, > wouldn't it be easier to just have a v4l2_subdev_state_get_format_stream > function and a static inline v4l2_subdev_state_get_format() that just calls > the _stream version with 0? I'm trying to shorten function names here: they're overly long. Also I'd like to see a single set of API functions to access sub-device state information irrespective of how it is stored. I originally proposed just specifying stream zero but both Laurent and Tomi opined against it.
Hi Sakari, On Wed, Oct 25, 2023 at 10:19:15AM +0000, Sakari Ailus wrote: > On Wed, Oct 25, 2023 at 11:53:35AM +0200, Hans Verkuil wrote: > > On 23/10/2023 19:44, 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> > > > --- > > > drivers/media/v4l2-core/v4l2-subdev.c | 18 ++++++------- > > > include/media/v4l2-subdev.h | 39 ++++++++++++++++++++------- > > > 2 files changed, 39 insertions(+), 18 deletions(-) > > > > > > diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c > > > index f0f0af48730f..e35226587244 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(struct v4l2_subdev_state *state, > > > + unsigned int pad, u32 stream) > > > { > > > struct v4l2_subdev_stream_configs *stream_configs; > > > unsigned int i; > > > @@ -1702,11 +1702,11 @@ 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); > > > > > > struct v4l2_rect * > > > -v4l2_subdev_state_get_crop(struct v4l2_subdev_state *state, unsigned int pad, > > > - u32 stream) > > > +__v4l2_subdev_state_get_crop(struct v4l2_subdev_state *state, unsigned int pad, > > > + u32 stream) > > > { > > > struct v4l2_subdev_stream_configs *stream_configs; > > > unsigned int i; > > > @@ -1736,11 +1736,11 @@ 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); > > > > > > struct v4l2_rect * > > > -v4l2_subdev_state_get_compose(struct v4l2_subdev_state *state, unsigned int pad, > > > - u32 stream) > > > +__v4l2_subdev_state_get_compose(struct v4l2_subdev_state *state, > > > + unsigned int pad, u32 stream) > > > { > > > struct v4l2_subdev_stream_configs *stream_configs; > > > unsigned int i; > > > @@ -1770,7 +1770,7 @@ 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); > > > > > > 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..12eb0fe746d7 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 +1553,22 @@ 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. > > > */ > > > +#define v4l2_subdev_state_get_format(state, pad, ...) \ > > > + __v4l2_subdev_state_get_format_ ## __VA_OPT__(stream) \ > > > + (state, pad __VA_OPT__(,) __VA_ARGS__) > > > +#define __v4l2_subdev_state_get_format_(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) > > > > Hmm, 'git grep __VA_OPT__' finds no use of this in the kernel. Are you sure this > > is safe to use? Does clang support it? Do all gcc versions that the kernel support > > implement it? > > > > A 10+ for creativity, but I'm a bit concerned about it. > > :-) > > I noticed the problem, too, as the lkp bot failed compiling this on GCC > 7.5. Indeed only GCC 8 supports __VA_OPT__ but the oldest GCC version > supported for kernel compilation is 7.1. So __VA_OPT__ isn't... an option. > > I thought this could be done using variable arguments, making most error > handling take place at runtime (for GCC versions not supporting > __VA_OPT__), but then Laurent figured this can be done with just > __VA_ARGS__ which is part of C99. > > The code would look like this, which is only slightly less understandable > than with __VA_OPT__: > > #define v4l2_subdev_state_get_format(...) \ > __v4l2_subdev_state_get_format_var(__VA_ARGS__, , _2)(__VA_ARGS__) How about __v4l2_subdev_state_get_format_var(__VA_ARGS__, _stream, _pad)(__VA_ARGS__) ? The internal macro and function names would then be more explicit. > #define __v4l2_subdev_state_get_format_var(_1, _2, _3, NUM, ...) \ > __v4l2_subdev_state_get_format ## NUM > #define __v4l2_subdev_state_get_format_2(state, pad) \ > __v4l2_subdev_state_get_format(state, pad, 0) > struct v4l2_mbus_framefmt * > __v4l2_subdev_state_get_format(struct v4l2_subdev_state *state, > unsigned int pad, u32 stream); > > > And if there are only a few drivers that need to give a specific stream, > > wouldn't it be easier to just have a v4l2_subdev_state_get_format_stream > > function and a static inline v4l2_subdev_state_get_format() that just calls > > the _stream version with 0? > > I'm trying to shorten function names here: they're overly long. Also I'd > like to see a single set of API functions to access sub-device state > information irrespective of how it is stored. I originally proposed just > specifying stream zero but both Laurent and Tomi opined against it.
Hi Laurent, On Wed, Oct 25, 2023 at 01:50:55PM +0300, Laurent Pinchart wrote: > Hi Sakari, > > On Wed, Oct 25, 2023 at 10:19:15AM +0000, Sakari Ailus wrote: > > On Wed, Oct 25, 2023 at 11:53:35AM +0200, Hans Verkuil wrote: > > > On 23/10/2023 19:44, 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> > > > > --- > > > > drivers/media/v4l2-core/v4l2-subdev.c | 18 ++++++------- > > > > include/media/v4l2-subdev.h | 39 ++++++++++++++++++++------- > > > > 2 files changed, 39 insertions(+), 18 deletions(-) > > > > > > > > diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c > > > > index f0f0af48730f..e35226587244 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(struct v4l2_subdev_state *state, > > > > + unsigned int pad, u32 stream) > > > > { > > > > struct v4l2_subdev_stream_configs *stream_configs; > > > > unsigned int i; > > > > @@ -1702,11 +1702,11 @@ 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); > > > > > > > > struct v4l2_rect * > > > > -v4l2_subdev_state_get_crop(struct v4l2_subdev_state *state, unsigned int pad, > > > > - u32 stream) > > > > +__v4l2_subdev_state_get_crop(struct v4l2_subdev_state *state, unsigned int pad, > > > > + u32 stream) > > > > { > > > > struct v4l2_subdev_stream_configs *stream_configs; > > > > unsigned int i; > > > > @@ -1736,11 +1736,11 @@ 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); > > > > > > > > struct v4l2_rect * > > > > -v4l2_subdev_state_get_compose(struct v4l2_subdev_state *state, unsigned int pad, > > > > - u32 stream) > > > > +__v4l2_subdev_state_get_compose(struct v4l2_subdev_state *state, > > > > + unsigned int pad, u32 stream) > > > > { > > > > struct v4l2_subdev_stream_configs *stream_configs; > > > > unsigned int i; > > > > @@ -1770,7 +1770,7 @@ 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); > > > > > > > > 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..12eb0fe746d7 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 +1553,22 @@ 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. > > > > */ > > > > +#define v4l2_subdev_state_get_format(state, pad, ...) \ > > > > + __v4l2_subdev_state_get_format_ ## __VA_OPT__(stream) \ > > > > + (state, pad __VA_OPT__(,) __VA_ARGS__) > > > > +#define __v4l2_subdev_state_get_format_(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) > > > > > > Hmm, 'git grep __VA_OPT__' finds no use of this in the kernel. Are you sure this > > > is safe to use? Does clang support it? Do all gcc versions that the kernel support > > > implement it? > > > > > > A 10+ for creativity, but I'm a bit concerned about it. > > > > :-) > > > > I noticed the problem, too, as the lkp bot failed compiling this on GCC > > 7.5. Indeed only GCC 8 supports __VA_OPT__ but the oldest GCC version > > supported for kernel compilation is 7.1. So __VA_OPT__ isn't... an option. > > > > I thought this could be done using variable arguments, making most error > > handling take place at runtime (for GCC versions not supporting > > __VA_OPT__), but then Laurent figured this can be done with just > > __VA_ARGS__ which is part of C99. > > > > The code would look like this, which is only slightly less understandable > > than with __VA_OPT__: > > > > #define v4l2_subdev_state_get_format(...) \ > > __v4l2_subdev_state_get_format_var(__VA_ARGS__, , _2)(__VA_ARGS__) > > How about > > __v4l2_subdev_state_get_format_var(__VA_ARGS__, _stream, _pad)(__VA_ARGS__) > > ? The internal macro and function names would then be more explicit. Works for me. I'll also rename __v4l2_subdev_state_get_format_var, removing _var. > > > #define __v4l2_subdev_state_get_format_var(_1, _2, _3, NUM, ...) \ > > __v4l2_subdev_state_get_format ## NUM > > #define __v4l2_subdev_state_get_format_2(state, pad) \ > > __v4l2_subdev_state_get_format(state, pad, 0) > > struct v4l2_mbus_framefmt * > > __v4l2_subdev_state_get_format(struct v4l2_subdev_state *state, > > unsigned int pad, u32 stream); > > > > > And if there are only a few drivers that need to give a specific stream, > > > wouldn't it be easier to just have a v4l2_subdev_state_get_format_stream > > > function and a static inline v4l2_subdev_state_get_format() that just calls > > > the _stream version with 0? > > > > I'm trying to shorten function names here: they're overly long. Also I'd > > like to see a single set of API functions to access sub-device state > > information irrespective of how it is stored. I originally proposed just > > specifying stream zero but both Laurent and Tomi opined against it. >
On 25/10/2023 12:19, Sakari Ailus wrote: > Hi Hans, > > Thank you for the review. > > On Wed, Oct 25, 2023 at 11:53:35AM +0200, Hans Verkuil wrote: >> On 23/10/2023 19:44, 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> >>> --- >>> drivers/media/v4l2-core/v4l2-subdev.c | 18 ++++++------- >>> include/media/v4l2-subdev.h | 39 ++++++++++++++++++++------- >>> 2 files changed, 39 insertions(+), 18 deletions(-) >>> >>> diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c >>> index f0f0af48730f..e35226587244 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(struct v4l2_subdev_state *state, >>> + unsigned int pad, u32 stream) >>> { >>> struct v4l2_subdev_stream_configs *stream_configs; >>> unsigned int i; >>> @@ -1702,11 +1702,11 @@ 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); >>> >>> struct v4l2_rect * >>> -v4l2_subdev_state_get_crop(struct v4l2_subdev_state *state, unsigned int pad, >>> - u32 stream) >>> +__v4l2_subdev_state_get_crop(struct v4l2_subdev_state *state, unsigned int pad, >>> + u32 stream) >>> { >>> struct v4l2_subdev_stream_configs *stream_configs; >>> unsigned int i; >>> @@ -1736,11 +1736,11 @@ 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); >>> >>> struct v4l2_rect * >>> -v4l2_subdev_state_get_compose(struct v4l2_subdev_state *state, unsigned int pad, >>> - u32 stream) >>> +__v4l2_subdev_state_get_compose(struct v4l2_subdev_state *state, >>> + unsigned int pad, u32 stream) >>> { >>> struct v4l2_subdev_stream_configs *stream_configs; >>> unsigned int i; >>> @@ -1770,7 +1770,7 @@ 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); >>> >>> 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..12eb0fe746d7 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 +1553,22 @@ 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. >>> */ >>> +#define v4l2_subdev_state_get_format(state, pad, ...) \ >>> + __v4l2_subdev_state_get_format_ ## __VA_OPT__(stream) \ >>> + (state, pad __VA_OPT__(,) __VA_ARGS__) >>> +#define __v4l2_subdev_state_get_format_(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) >> >> Hmm, 'git grep __VA_OPT__' finds no use of this in the kernel. Are you sure this >> is safe to use? Does clang support it? Do all gcc versions that the kernel support >> implement it? >> >> A 10+ for creativity, but I'm a bit concerned about it. > > :-) > > I noticed the problem, too, as the lkp bot failed compiling this on GCC > 7.5. Indeed only GCC 8 supports __VA_OPT__ but the oldest GCC version > supported for kernel compilation is 7.1. So __VA_OPT__ isn't... an option. > > I thought this could be done using variable arguments, making most error > handling take place at runtime (for GCC versions not supporting > __VA_OPT__), but then Laurent figured this can be done with just > __VA_ARGS__ which is part of C99. > > The code would look like this, which is only slightly less understandable > than with __VA_OPT__: > > #define v4l2_subdev_state_get_format(...) \ > __v4l2_subdev_state_get_format_var(__VA_ARGS__, , _2)(__VA_ARGS__) > #define __v4l2_subdev_state_get_format_var(_1, _2, _3, NUM, ...) \ > __v4l2_subdev_state_get_format ## NUM > #define __v4l2_subdev_state_get_format_2(state, pad) \ > __v4l2_subdev_state_get_format(state, pad, 0) > struct v4l2_mbus_framefmt * > __v4l2_subdev_state_get_format(struct v4l2_subdev_state *state, > unsigned int pad, u32 stream); Wow! OK, I guess that will work. A strongly suggest adding a comment before this explaining what you are trying to achieve. It's not exactly obvious :-) Regards, Hans > >> >> And if there are only a few drivers that need to give a specific stream, >> wouldn't it be easier to just have a v4l2_subdev_state_get_format_stream >> function and a static inline v4l2_subdev_state_get_format() that just calls >> the _stream version with 0? > > I'm trying to shorten function names here: they're overly long. Also I'd > like to see a single set of API functions to access sub-device state > information irrespective of how it is stored. I originally proposed just > specifying stream zero but both Laurent and Tomi opined against it. >
Hi Hans, On Wed, Oct 25, 2023 at 01:20:29PM +0200, Hans Verkuil wrote: > On 25/10/2023 12:19, Sakari Ailus wrote: > > Hi Hans, > > > > Thank you for the review. > > > > On Wed, Oct 25, 2023 at 11:53:35AM +0200, Hans Verkuil wrote: > >> On 23/10/2023 19:44, 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> > >>> --- > >>> drivers/media/v4l2-core/v4l2-subdev.c | 18 ++++++------- > >>> include/media/v4l2-subdev.h | 39 ++++++++++++++++++++------- > >>> 2 files changed, 39 insertions(+), 18 deletions(-) > >>> > >>> diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c > >>> index f0f0af48730f..e35226587244 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(struct v4l2_subdev_state *state, > >>> + unsigned int pad, u32 stream) > >>> { > >>> struct v4l2_subdev_stream_configs *stream_configs; > >>> unsigned int i; > >>> @@ -1702,11 +1702,11 @@ 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); > >>> > >>> struct v4l2_rect * > >>> -v4l2_subdev_state_get_crop(struct v4l2_subdev_state *state, unsigned int pad, > >>> - u32 stream) > >>> +__v4l2_subdev_state_get_crop(struct v4l2_subdev_state *state, unsigned int pad, > >>> + u32 stream) > >>> { > >>> struct v4l2_subdev_stream_configs *stream_configs; > >>> unsigned int i; > >>> @@ -1736,11 +1736,11 @@ 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); > >>> > >>> struct v4l2_rect * > >>> -v4l2_subdev_state_get_compose(struct v4l2_subdev_state *state, unsigned int pad, > >>> - u32 stream) > >>> +__v4l2_subdev_state_get_compose(struct v4l2_subdev_state *state, > >>> + unsigned int pad, u32 stream) > >>> { > >>> struct v4l2_subdev_stream_configs *stream_configs; > >>> unsigned int i; > >>> @@ -1770,7 +1770,7 @@ 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); > >>> > >>> 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..12eb0fe746d7 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 +1553,22 @@ 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. > >>> */ > >>> +#define v4l2_subdev_state_get_format(state, pad, ...) \ > >>> + __v4l2_subdev_state_get_format_ ## __VA_OPT__(stream) \ > >>> + (state, pad __VA_OPT__(,) __VA_ARGS__) > >>> +#define __v4l2_subdev_state_get_format_(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) > >> > >> Hmm, 'git grep __VA_OPT__' finds no use of this in the kernel. Are you sure this > >> is safe to use? Does clang support it? Do all gcc versions that the kernel support > >> implement it? > >> > >> A 10+ for creativity, but I'm a bit concerned about it. > > > > :-) > > > > I noticed the problem, too, as the lkp bot failed compiling this on GCC > > 7.5. Indeed only GCC 8 supports __VA_OPT__ but the oldest GCC version > > supported for kernel compilation is 7.1. So __VA_OPT__ isn't... an option. > > > > I thought this could be done using variable arguments, making most error > > handling take place at runtime (for GCC versions not supporting > > __VA_OPT__), but then Laurent figured this can be done with just > > __VA_ARGS__ which is part of C99. > > > > The code would look like this, which is only slightly less understandable > > than with __VA_OPT__: > > > > #define v4l2_subdev_state_get_format(...) \ > > __v4l2_subdev_state_get_format_var(__VA_ARGS__, , _2)(__VA_ARGS__) > > #define __v4l2_subdev_state_get_format_var(_1, _2, _3, NUM, ...) \ > > __v4l2_subdev_state_get_format ## NUM > > #define __v4l2_subdev_state_get_format_2(state, pad) \ > > __v4l2_subdev_state_get_format(state, pad, 0) > > struct v4l2_mbus_framefmt * > > __v4l2_subdev_state_get_format(struct v4l2_subdev_state *state, > > unsigned int pad, u32 stream); > > Wow! OK, I guess that will work. > > A strongly suggest adding a comment before this explaining what you are > trying to achieve. It's not exactly obvious :-) I'll add: /* * 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. */
diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c index f0f0af48730f..e35226587244 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(struct v4l2_subdev_state *state, + unsigned int pad, u32 stream) { struct v4l2_subdev_stream_configs *stream_configs; unsigned int i; @@ -1702,11 +1702,11 @@ 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); struct v4l2_rect * -v4l2_subdev_state_get_crop(struct v4l2_subdev_state *state, unsigned int pad, - u32 stream) +__v4l2_subdev_state_get_crop(struct v4l2_subdev_state *state, unsigned int pad, + u32 stream) { struct v4l2_subdev_stream_configs *stream_configs; unsigned int i; @@ -1736,11 +1736,11 @@ 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); struct v4l2_rect * -v4l2_subdev_state_get_compose(struct v4l2_subdev_state *state, unsigned int pad, - u32 stream) +__v4l2_subdev_state_get_compose(struct v4l2_subdev_state *state, + unsigned int pad, u32 stream) { struct v4l2_subdev_stream_configs *stream_configs; unsigned int i; @@ -1770,7 +1770,7 @@ 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); 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..12eb0fe746d7 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 +1553,22 @@ 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. */ +#define v4l2_subdev_state_get_format(state, pad, ...) \ + __v4l2_subdev_state_get_format_ ## __VA_OPT__(stream) \ + (state, pad __VA_OPT__(,) __VA_ARGS__) +#define __v4l2_subdev_state_get_format_(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); +__v4l2_subdev_state_get_format(struct v4l2_subdev_state *state, + unsigned int pad, u32 stream); /** * 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 +1576,22 @@ 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(state, pad, ...) \ + __v4l2_subdev_state_get_crop_ ## __VA_OPT__(stream) \ + (state, pad __VA_OPT__(,) __VA_ARGS__) +#define __v4l2_subdev_state_get_crop_(state, pad) \ + __v4l2_subdev_state_get_crop(state, pad, 0) +#define __v4l2_subdev_state_get_crop_stream(state, pad, stream) \ + __v4l2_subdev_state_get_crop(state, pad, stream) struct v4l2_rect * -v4l2_subdev_state_get_crop(struct v4l2_subdev_state *state, unsigned int pad, - u32 stream); +__v4l2_subdev_state_get_crop(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 +1599,16 @@ 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(state, pad, ...) \ + __v4l2_subdev_state_get_compose_ ## __VA_OPT__(stream) \ + (state, pad __VA_OPT__(,) __VA_ARGS__) +#define __v4l2_subdev_state_get_compose_(state, pad) \ + __v4l2_subdev_state_get_compose(state, pad, 0) +#define __v4l2_subdev_state_get_compose_stream(state, pad, stream) \ + __v4l2_subdev_state_get_compose(state, pad, stream) struct v4l2_rect * -v4l2_subdev_state_get_compose(struct v4l2_subdev_state *state, unsigned int pad, - u32 stream); +__v4l2_subdev_state_get_compose(struct v4l2_subdev_state *state, + unsigned int pad, u32 stream); /** * v4l2_subdev_routing_find_opposite_end() - Find the opposite stream
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> --- drivers/media/v4l2-core/v4l2-subdev.c | 18 ++++++------- include/media/v4l2-subdev.h | 39 ++++++++++++++++++++------- 2 files changed, 39 insertions(+), 18 deletions(-)