Hi Laurent,
Thanks for the comments!
Laurent Pinchart wrote:
> On Tuesday 20 December 2011 21:27:56 Sakari Ailus wrote:
>> From: Sakari Ailus <sakari.ailus@xxxxxx>
>>
>> Add support for VIDIOC_SUBDEV_S_SELECTION and VIDIOC_SUBDEV_G_SELECTION
>> IOCTLs. They replace functionality provided by VIDIOC_SUBDEV_S_CROP and
>> VIDIOC_SUBDEV_G_CROP IOCTLs and also add new functionality (composing).
>>
>> VIDIOC_SUBDEV_G_CROP and VIDIOC_SUBDEV_S_CROP continue to be supported.
>
> As those ioctls are experimental, should we deprecate them ?
I'm also in favour of doing that. But I'll make it a separate patch.
>> Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxx>
>> ---
>> drivers/media/video/v4l2-subdev.c | 26 ++++++++++++++++++++-
>> include/linux/v4l2-subdev.h | 45 ++++++++++++++++++++++++++++++++++
>> include/media/v4l2-subdev.h | 5 ++++
>> 3 files changed, 75 insertions(+), 1 deletions(-)
>>
>> diff --git a/drivers/media/video/v4l2-subdev.c
>> b/drivers/media/video/v4l2-subdev.c index 65ade5f..e8ae098 100644
>> --- a/drivers/media/video/v4l2-subdev.c
>> +++ b/drivers/media/video/v4l2-subdev.c
>> @@ -36,13 +36,17 @@ static int subdev_fh_init(struct v4l2_subdev_fh *fh,
>> struct v4l2_subdev *sd) {
>> #if defined(CONFIG_VIDEO_V4L2_SUBDEV_API)
>> /* Allocate try format and crop in the same memory block */
>> - fh->try_fmt = kzalloc((sizeof(*fh->try_fmt) + sizeof(*fh->try_crop))
>> + fh->try_fmt = kzalloc((sizeof(*fh->try_fmt) + sizeof(*fh->try_crop)
>> + + sizeof(*fh->try_compose))
>> * sd->entity.num_pads, GFP_KERNEL);
>
> Could you check how the 3 structures are aligned on 64-bit platforms ? I'm a
> bit worried about the compiler expecting a 64-bit alignment for one of them,
> and getting only a 32-bit alignment in the end.
>
> What about using kcalloc ?
kcalloc won't make a difference --- see the implementation. Do you think
this is really an issue in practice?
If we want to ensure alignment I'd just allocate them separately. Or
create a struct out of them locally, and get the pointers from that
struct --- then the alignment would be the same as if those were part of
a single struct. That achieves the desired result and also keeps error
handling trivial.
I wouldn't want to start relying on the alignment based on the sizes of
these structures.
>> if (fh->try_fmt == NULL)
>> return -ENOMEM;
>>
>> fh->try_crop = (struct v4l2_rect *)
>> (fh->try_fmt + sd->entity.num_pads);
>> +
>> + fh->try_compose = (struct v4l2_rect *)
>> + (fh->try_crop + sd->entity.num_pads);
>> #endif
>> return 0;
>> }
>> @@ -281,6 +285,26 @@ static long subdev_do_ioctl(struct file *file,
>> unsigned int cmd, void *arg) return v4l2_subdev_call(sd, pad,
>> enum_frame_interval, subdev_fh, fie);
>> }
>> +
>> + case VIDIOC_SUBDEV_G_SELECTION: {
>> + struct v4l2_subdev_selection *sel = arg;
>
> Shouldn't you check sel->which ?
Yes.
>> + if (sel->pad >= sd->entity.num_pads)
>> + return -EINVAL;
>> +
>> + return v4l2_subdev_call(
>> + sd, pad, get_selection, subdev_fh, sel);
>> + }
>> +
>> + case VIDIOC_SUBDEV_S_SELECTION: {
>> + struct v4l2_subdev_selection *sel = arg;
>
> And here too ?
Yes.
>> + if (sel->pad >= sd->entity.num_pads)
>> + return -EINVAL;
>> +
>> + return v4l2_subdev_call(
>> + sd, pad, set_selection, subdev_fh, sel);
>> + }
>> #endif
>> default:
>> return v4l2_subdev_call(sd, core, ioctl, cmd, arg);
>> diff --git a/include/linux/v4l2-subdev.h b/include/linux/v4l2-subdev.h
>> index ed29cbb..d53d775 100644
>> --- a/include/linux/v4l2-subdev.h
>> +++ b/include/linux/v4l2-subdev.h
>> @@ -123,6 +123,47 @@ struct v4l2_subdev_frame_interval_enum {
>> __u32 reserved[9];
>> };
>>
>> +#define V4L2_SUBDEV_SEL_FLAG_SIZE_GE (1 << 0)
>> +#define V4L2_SUBDEV_SEL_FLAG_SIZE_LE (1 << 1)
>> +#define V4L2_SUBDEV_SEL_FLAG_KEEP_CONFIG (1 << 2)
>> +
>> +/* active cropping area */
>> +#define V4L2_SUBDEV_SEL_TGT_CROP_ACTIVE 0
>> +/* default cropping area */
>> +#define V4L2_SUBDEV_SEL_TGT_CROP_DEFAULT 1
>> +/* cropping bounds */
>> +#define V4L2_SUBDEV_SEL_TGT_CROP_BOUNDS 2
>> +/* current composing area */
>> +#define V4L2_SUBDEV_SEL_TGT_COMPOSE_ACTIVE 256
>> +/* default composing area */
>> +#define V4L2_SUBDEV_SEL_TGT_COMPOSE_DEFAULT 257
>> +/* composing bounds */
>> +#define V4L2_SUBDEV_SEL_TGT_COMPOSE_BOUNDS 258
>> +
>> +
>> +/**
>> + * struct v4l2_subdev_selection - selection info
>> + *
>> + * @which: either V4L2_SUBDEV_FORMAT_ACTIVE or V4L2_SUBDEV_FORMAT_TRY
>> + * @pad: pad number, as reported by the media API
>> + * @target: selection target, used to choose one of possible rectangles
>> + * @flags: constraints flags
>> + * @r: coordinates of selection window
>> + * @reserved: for future use, rounds structure size to 64 bytes, set to
>> zero + *
>> + * Hardware may use multiple helper window to process a video stream.
>> + * The structure is used to exchange this selection areas between
>> + * an application and a driver.
>> + */
>> +struct v4l2_subdev_selection {
>> + __u32 which;
>> + __u32 pad;
>> + __u32 target;
>> + __u32 flags;
>> + struct v4l2_rect r;
>> + __u32 reserved[8];
>> +};
>> +
>> #define VIDIOC_SUBDEV_G_FMT _IOWR('V', 4, struct v4l2_subdev_format)
>> #define VIDIOC_SUBDEV_S_FMT _IOWR('V', 5, struct v4l2_subdev_format)
>> #define VIDIOC_SUBDEV_G_FRAME_INTERVAL \
>> @@ -137,5 +178,9 @@ struct v4l2_subdev_frame_interval_enum {
>> _IOWR('V', 75, struct v4l2_subdev_frame_interval_enum)
>> #define VIDIOC_SUBDEV_G_CROP _IOWR('V', 59, struct v4l2_subdev_crop)
>> #define VIDIOC_SUBDEV_S_CROP _IOWR('V', 60, struct v4l2_subdev_crop)
>> +#define VIDIOC_SUBDEV_G_SELECTION \
>> + _IOWR('V', 61, struct v4l2_subdev_selection)
>> +#define VIDIOC_SUBDEV_S_SELECTION \
>> + _IOWR('V', 62, struct v4l2_subdev_selection)
>>
>> #endif
>> diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h
>> index f0f3358..26eeaa4 100644
>> --- a/include/media/v4l2-subdev.h
>> +++ b/include/media/v4l2-subdev.h
>> @@ -466,6 +466,10 @@ struct v4l2_subdev_pad_ops {
>> struct v4l2_subdev_crop *crop);
>> int (*get_crop)(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh,
>> struct v4l2_subdev_crop *crop);
>> + int (*get_selection)(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh,
>> + struct v4l2_subdev_selection *sel);
>> + int (*set_selection)(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh,
>> + struct v4l2_subdev_selection *sel);
>> };
>>
>> struct v4l2_subdev_ops {
>> @@ -551,6 +555,7 @@ struct v4l2_subdev_fh {
>> #if defined(CONFIG_VIDEO_V4L2_SUBDEV_API)
>> struct v4l2_mbus_framefmt *try_fmt;
>> struct v4l2_rect *try_crop;
>> + struct v4l2_rect *try_compose;
>> #endif
>> };
>
--
Sakari Ailus
sakari.ailus@xxxxxxxxxxxxxxxxxxxxxxxxxx
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