Re: [PATCH v4 4/7] media: v4l2-subdev: add stubs for v4l2_subdev_get_try_*

Hi Jacopo,

On 19-03-21 11:01, Jacopo Mondi wrote:

Hi Marco,

FYI we've been there already:
https://patchwork.kernel.org/patch/10703029/

and that ended with Hans' patch:
https://patchwork.linuxtv.org/patch/53370/
which didn't get far unfortunately.

Thanks for this links :) It seems that there isn't a simple solution.

On Tue, Jan 29, 2019 at 05:07:54PM +0100, Marco Felsch wrote:

quoted

In case of missing CONFIG_VIDEO_V4L2_SUBDEV_API those helpers aren't
available. So each driver have to add ifdefs around those helpers or
add the CONFIG_VIDEO_V4L2_SUBDEV_API as dependcy.

Make these helpers available in case of CONFIG_VIDEO_V4L2_SUBDEV_API
isn't set to avoid ifdefs. This approach is less error prone too.

Signed-off-by: Marco Felsch <redacted>
---
 include/media/v4l2-subdev.h | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h
index 47af609dc8f1..90c9a301d72a 100644
--- a/include/media/v4l2-subdev.h
+++ b/include/media/v4l2-subdev.h

@@ -916,8 +916,6 @@ struct v4l2_subdev_fh {
 #define to_v4l2_subdev_fh(fh)	\
 	container_of(fh, struct v4l2_subdev_fh, vfh)

-#if defined(CONFIG_VIDEO_V4L2_SUBDEV_API)
-
 /**
  * v4l2_subdev_get_try_format - ancillary routine to call
  *	&struct v4l2_subdev_pad_config->try_fmt

@@ -931,9 +929,13 @@ static inline struct v4l2_mbus_framefmt
 			    struct v4l2_subdev_pad_config *cfg,
 			    unsigned int pad)
 {
+#if defined(CONFIG_VIDEO_V4L2_SUBDEV_API)
 	if (WARN_ON(pad >= sd->entity.num_pads))
 		pad = 0;
 	return &cfg[pad].try_fmt;
+#else
+	return NULL;

Since Hans' attempt didn't succeed, maybe we want to reconsider this
approach? I liked Lubomir's version better, but in any case, small
details...

Shouldn't you return ERR_PTR(-ENOTTY) here instead of NULL ?

Yes that would be better.

+ Sakari, Hans:
Alternatively, what if we add CONFIG_VIDEO_V4L2_SUBDEV_API as a
dependency of all sensor drivers that still use the

#ifdef CONFIG_VIDEO_V4L2_SUBDEV_API
v4l2_subdev_get_try_format(sd, cfg, format->pad);
#else
-ENOTTY
#endif

pattern so we could remove that block #ifdef blocks and do not touch the
v4l2-subdev.h header? Should I send a patch?

If I remember rightly the mt9v111 is using the dependency approach to
avoid such ifdef's too. But this seems like Hans approach if I got it
right which wasn't ok for Mauro.

Regards,
Marco

Thanks
  j

quoted

+#endif
 }

 /**

@@ -949,9 +951,13 @@ static inline struct v4l2_rect
 			  struct v4l2_subdev_pad_config *cfg,
 			  unsigned int pad)
 {
+#if defined(CONFIG_VIDEO_V4L2_SUBDEV_API)
 	if (WARN_ON(pad >= sd->entity.num_pads))
 		pad = 0;
 	return &cfg[pad].try_crop;
+#else
+	return NULL;
+#endif
 }

 /**

@@ -967,11 +973,14 @@ static inline struct v4l2_rect
 			     struct v4l2_subdev_pad_config *cfg,
 			     unsigned int pad)
 {
+#if defined(CONFIG_VIDEO_V4L2_SUBDEV_API)
 	if (WARN_ON(pad >= sd->entity.num_pads))
 		pad = 0;
 	return &cfg[pad].try_compose;
-}
+#else
+	return NULL;
 #endif
+}

 extern const struct v4l2_file_operations v4l2_subdev_fops;

--

2.20.1

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