[PATCH] media: v4l2-subdev: Fix stream handling for crop API

[PATCH] media: v4l2-subdev: Fix stream handling for crop API

[Laurent Pinchart]

When support for streams was added to the V4L2 subdev API, the
v4l2_subdev_crop structure was extended with a stream field, but the
field was not handled in the core code that translates the
VIDIOC_SUBDEV_[GS]_CROP ioctls to the selection API. Fix it.

Fixes: 2f91e10ee6fd ("media: subdev: add stream based configuration")
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 drivers/media/v4l2-core/v4l2-subdev.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
index 4c6198c48dd6..45836f0a2b0a 100644
--- a/drivers/media/v4l2-core/v4l2-subdev.c
+++ b/drivers/media/v4l2-core/v4l2-subdev.c
@@ -732,6 +732,7 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg,
 		memset(&sel, 0, sizeof(sel));
 		sel.which = crop->which;
 		sel.pad = crop->pad;
+		sel.stream = crop->stream;
 		sel.target = V4L2_SEL_TGT_CROP;
 
 		rval = v4l2_subdev_call(
@@ -756,6 +757,7 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg,
 		memset(&sel, 0, sizeof(sel));
 		sel.which = crop->which;
 		sel.pad = crop->pad;
+		sel.stream = crop->stream;
 		sel.target = V4L2_SEL_TGT_CROP;
 		sel.r = crop->rect;
 

base-commit: 39cd87c4eb2b893354f3b850f916353f2658ae6f
-- 
Regards,

Laurent Pinchart

Re: [PATCH] media: v4l2-subdev: Fix stream handling for crop API

[Tomi Valkeinen]

On 02/04/2024 02:37, Laurent Pinchart wrote:
> When support for streams was added to the V4L2 subdev API, the
> v4l2_subdev_crop structure was extended with a stream field, but the
> field was not handled in the core code that translates the
> VIDIOC_SUBDEV_[GS]_CROP ioctls to the selection API. Fix it.
> 
> Fixes: 2f91e10ee6fd ("media: subdev: add stream based configuration")
> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> ---
>   drivers/media/v4l2-core/v4l2-subdev.c | 2 ++
>   1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
> index 4c6198c48dd6..45836f0a2b0a 100644
> --- a/drivers/media/v4l2-core/v4l2-subdev.c
> +++ b/drivers/media/v4l2-core/v4l2-subdev.c
> @@ -732,6 +732,7 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg,
>   		memset(&sel, 0, sizeof(sel));
>   		sel.which = crop->which;
>   		sel.pad = crop->pad;
> +		sel.stream = crop->stream;
>   		sel.target = V4L2_SEL_TGT_CROP;
>   
>   		rval = v4l2_subdev_call(
> @@ -756,6 +757,7 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg,
>   		memset(&sel, 0, sizeof(sel));
>   		sel.which = crop->which;
>   		sel.pad = crop->pad;
> +		sel.stream = crop->stream;
>   		sel.target = V4L2_SEL_TGT_CROP;
>   		sel.r = crop->rect;
>   
> 
> base-commit: 39cd87c4eb2b893354f3b850f916353f2658ae6f

Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>

  Tomi

Re: [PATCH] media: v4l2-subdev: Fix stream handling for crop API

[Sakari Ailus]

Moi,

On Tue, Apr 02, 2024 at 02:37:25AM +0300, Laurent Pinchart wrote:
> When support for streams was added to the V4L2 subdev API, the
> v4l2_subdev_crop structure was extended with a stream field, but the
> field was not handled in the core code that translates the
> VIDIOC_SUBDEV_[GS]_CROP ioctls to the selection API. Fix it.

The field is indeed in the UAPI headers. But do we want to support the CROP
IOCTL for streams? Shouldn't the callers be using the [GS]_SELECTION
instead?

> 
> Fixes: 2f91e10ee6fd ("media: subdev: add stream based configuration")
> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> ---
>  drivers/media/v4l2-core/v4l2-subdev.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
> index 4c6198c48dd6..45836f0a2b0a 100644
> --- a/drivers/media/v4l2-core/v4l2-subdev.c
> +++ b/drivers/media/v4l2-core/v4l2-subdev.c
> @@ -732,6 +732,7 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg,
>  		memset(&sel, 0, sizeof(sel));
>  		sel.which = crop->which;
>  		sel.pad = crop->pad;
> +		sel.stream = crop->stream;
>  		sel.target = V4L2_SEL_TGT_CROP;
>  
>  		rval = v4l2_subdev_call(
> @@ -756,6 +757,7 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg,
>  		memset(&sel, 0, sizeof(sel));
>  		sel.which = crop->which;
>  		sel.pad = crop->pad;
> +		sel.stream = crop->stream;
>  		sel.target = V4L2_SEL_TGT_CROP;
>  		sel.r = crop->rect;
>  
> 
> base-commit: 39cd87c4eb2b893354f3b850f916353f2658ae6f

-- 
Terveisin,

Sakari Ailus

Re: [PATCH] media: v4l2-subdev: Fix stream handling for crop API

[Laurent Pinchart]

On Tue, Apr 02, 2024 at 08:20:22AM +0000, Sakari Ailus wrote:
> Moi,
> 
> On Tue, Apr 02, 2024 at 02:37:25AM +0300, Laurent Pinchart wrote:
> > When support for streams was added to the V4L2 subdev API, the
> > v4l2_subdev_crop structure was extended with a stream field, but the
> > field was not handled in the core code that translates the
> > VIDIOC_SUBDEV_[GS]_CROP ioctls to the selection API. Fix it.
> 
> The field is indeed in the UAPI headers. But do we want to support the CROP
> IOCTL for streams? Shouldn't the callers be using the [GS]_SELECTION
> instead?

They should, but if the field is there, we should support it :-) The
alternative is to remove it. It will cause failures in v4l2-compliance
that we'll need to handle though.

> > Fixes: 2f91e10ee6fd ("media: subdev: add stream based configuration")
> > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > ---
> >  drivers/media/v4l2-core/v4l2-subdev.c | 2 ++
> >  1 file changed, 2 insertions(+)
> > 
> > diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
> > index 4c6198c48dd6..45836f0a2b0a 100644
> > --- a/drivers/media/v4l2-core/v4l2-subdev.c
> > +++ b/drivers/media/v4l2-core/v4l2-subdev.c
> > @@ -732,6 +732,7 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg,
> >  		memset(&sel, 0, sizeof(sel));
> >  		sel.which = crop->which;
> >  		sel.pad = crop->pad;
> > +		sel.stream = crop->stream;
> >  		sel.target = V4L2_SEL_TGT_CROP;
> >  
> >  		rval = v4l2_subdev_call(
> > @@ -756,6 +757,7 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg,
> >  		memset(&sel, 0, sizeof(sel));
> >  		sel.which = crop->which;
> >  		sel.pad = crop->pad;
> > +		sel.stream = crop->stream;
> >  		sel.target = V4L2_SEL_TGT_CROP;
> >  		sel.r = crop->rect;
> >  
> > 
> > base-commit: 39cd87c4eb2b893354f3b850f916353f2658ae6f

-- 
Regards,

Laurent Pinchart

Re: [PATCH] media: v4l2-subdev: Fix stream handling for crop API

[Sakari Ailus]

On Tue, Apr 02, 2024 at 11:44:07AM +0300, Laurent Pinchart wrote:
> On Tue, Apr 02, 2024 at 08:20:22AM +0000, Sakari Ailus wrote:
> > Moi,
> > 
> > On Tue, Apr 02, 2024 at 02:37:25AM +0300, Laurent Pinchart wrote:
> > > When support for streams was added to the V4L2 subdev API, the
> > > v4l2_subdev_crop structure was extended with a stream field, but the
> > > field was not handled in the core code that translates the
> > > VIDIOC_SUBDEV_[GS]_CROP ioctls to the selection API. Fix it.
> > 
> > The field is indeed in the UAPI headers. But do we want to support the CROP
> > IOCTL for streams? Shouldn't the callers be using the [GS]_SELECTION
> > instead?
> 
> They should, but if the field is there, we should support it :-) The
> alternative is to remove it. It will cause failures in v4l2-compliance
> that we'll need to handle though.

I'd prefer to stick to selections here, this is new functionality so
[GS]_CROP support isn't required. I don't have a strong opinion on the
matter though.

> 
> > > Fixes: 2f91e10ee6fd ("media: subdev: add stream based configuration")
> > > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > > ---
> > >  drivers/media/v4l2-core/v4l2-subdev.c | 2 ++
> > >  1 file changed, 2 insertions(+)
> > > 
> > > diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
> > > index 4c6198c48dd6..45836f0a2b0a 100644
> > > --- a/drivers/media/v4l2-core/v4l2-subdev.c
> > > +++ b/drivers/media/v4l2-core/v4l2-subdev.c
> > > @@ -732,6 +732,7 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg,
> > >  		memset(&sel, 0, sizeof(sel));
> > >  		sel.which = crop->which;
> > >  		sel.pad = crop->pad;
> > > +		sel.stream = crop->stream;
> > >  		sel.target = V4L2_SEL_TGT_CROP;
> > >  
> > >  		rval = v4l2_subdev_call(
> > > @@ -756,6 +757,7 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg,
> > >  		memset(&sel, 0, sizeof(sel));
> > >  		sel.which = crop->which;
> > >  		sel.pad = crop->pad;
> > > +		sel.stream = crop->stream;
> > >  		sel.target = V4L2_SEL_TGT_CROP;
> > >  		sel.r = crop->rect;
> > >  
> > > 
> > > base-commit: 39cd87c4eb2b893354f3b850f916353f2658ae6f
> 
> -- 
> Regards,
> 
> Laurent Pinchart

-- 
Sakari Ailus

Re: [PATCH] media: v4l2-subdev: Fix stream handling for crop API

[Tomi Valkeinen]

On 02/04/2024 11:46, Sakari Ailus wrote:
> On Tue, Apr 02, 2024 at 11:44:07AM +0300, Laurent Pinchart wrote:
>> On Tue, Apr 02, 2024 at 08:20:22AM +0000, Sakari Ailus wrote:
>>> Moi,
>>>
>>> On Tue, Apr 02, 2024 at 02:37:25AM +0300, Laurent Pinchart wrote:
>>>> When support for streams was added to the V4L2 subdev API, the
>>>> v4l2_subdev_crop structure was extended with a stream field, but the
>>>> field was not handled in the core code that translates the
>>>> VIDIOC_SUBDEV_[GS]_CROP ioctls to the selection API. Fix it.
>>>
>>> The field is indeed in the UAPI headers. But do we want to support the CROP
>>> IOCTL for streams? Shouldn't the callers be using the [GS]_SELECTION
>>> instead?
>>
>> They should, but if the field is there, we should support it :-) The
>> alternative is to remove it. It will cause failures in v4l2-compliance
>> that we'll need to handle though.
> 
> I'd prefer to stick to selections here, this is new functionality so
> [GS]_CROP support isn't required. I don't have a strong opinion on the
> matter though.

Maybe it's easier to just support the stream field, instead of making 
[GS]_CROP the odd case which looks like it should support streams, but 
then doesn't...

  Tomi

>>
>>>> Fixes: 2f91e10ee6fd ("media: subdev: add stream based configuration")
>>>> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
>>>> ---
>>>>   drivers/media/v4l2-core/v4l2-subdev.c | 2 ++
>>>>   1 file changed, 2 insertions(+)
>>>>
>>>> diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
>>>> index 4c6198c48dd6..45836f0a2b0a 100644
>>>> --- a/drivers/media/v4l2-core/v4l2-subdev.c
>>>> +++ b/drivers/media/v4l2-core/v4l2-subdev.c
>>>> @@ -732,6 +732,7 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg,
>>>>   		memset(&sel, 0, sizeof(sel));
>>>>   		sel.which = crop->which;
>>>>   		sel.pad = crop->pad;
>>>> +		sel.stream = crop->stream;
>>>>   		sel.target = V4L2_SEL_TGT_CROP;
>>>>   
>>>>   		rval = v4l2_subdev_call(
>>>> @@ -756,6 +757,7 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg,
>>>>   		memset(&sel, 0, sizeof(sel));
>>>>   		sel.which = crop->which;
>>>>   		sel.pad = crop->pad;
>>>> +		sel.stream = crop->stream;
>>>>   		sel.target = V4L2_SEL_TGT_CROP;
>>>>   		sel.r = crop->rect;
>>>>   
>>>>
>>>> base-commit: 39cd87c4eb2b893354f3b850f916353f2658ae6f
>>
>> -- 
>> Regards,
>>
>> Laurent Pinchart
> 

Re: [PATCH] media: v4l2-subdev: Fix stream handling for crop API

[Laurent Pinchart]

On Tue, Apr 02, 2024 at 12:11:30PM +0300, Tomi Valkeinen wrote:
> On 02/04/2024 11:46, Sakari Ailus wrote:
> > On Tue, Apr 02, 2024 at 11:44:07AM +0300, Laurent Pinchart wrote:
> >> On Tue, Apr 02, 2024 at 08:20:22AM +0000, Sakari Ailus wrote:
> >>> Moi,
> >>>
> >>> On Tue, Apr 02, 2024 at 02:37:25AM +0300, Laurent Pinchart wrote:
> >>>> When support for streams was added to the V4L2 subdev API, the
> >>>> v4l2_subdev_crop structure was extended with a stream field, but the
> >>>> field was not handled in the core code that translates the
> >>>> VIDIOC_SUBDEV_[GS]_CROP ioctls to the selection API. Fix it.
> >>>
> >>> The field is indeed in the UAPI headers. But do we want to support the CROP
> >>> IOCTL for streams? Shouldn't the callers be using the [GS]_SELECTION
> >>> instead?
> >>
> >> They should, but if the field is there, we should support it :-) The
> >> alternative is to remove it. It will cause failures in v4l2-compliance
> >> that we'll need to handle though.
> > 
> > I'd prefer to stick to selections here, this is new functionality so
> > [GS]_CROP support isn't required. I don't have a strong opinion on the
> > matter though.
> 
> Maybe it's easier to just support the stream field, instead of making 
> [GS]_CROP the odd case which looks like it should support streams, but 
> then doesn't...

I'll let the two of you argue and decide, and implement the result :-)

> >>>> Fixes: 2f91e10ee6fd ("media: subdev: add stream based configuration")
> >>>> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> >>>> ---
> >>>>   drivers/media/v4l2-core/v4l2-subdev.c | 2 ++
> >>>>   1 file changed, 2 insertions(+)
> >>>>
> >>>> diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
> >>>> index 4c6198c48dd6..45836f0a2b0a 100644
> >>>> --- a/drivers/media/v4l2-core/v4l2-subdev.c
> >>>> +++ b/drivers/media/v4l2-core/v4l2-subdev.c
> >>>> @@ -732,6 +732,7 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg,
> >>>>   		memset(&sel, 0, sizeof(sel));
> >>>>   		sel.which = crop->which;
> >>>>   		sel.pad = crop->pad;
> >>>> +		sel.stream = crop->stream;
> >>>>   		sel.target = V4L2_SEL_TGT_CROP;
> >>>>   
> >>>>   		rval = v4l2_subdev_call(
> >>>> @@ -756,6 +757,7 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg,
> >>>>   		memset(&sel, 0, sizeof(sel));
> >>>>   		sel.which = crop->which;
> >>>>   		sel.pad = crop->pad;
> >>>> +		sel.stream = crop->stream;
> >>>>   		sel.target = V4L2_SEL_TGT_CROP;
> >>>>   		sel.r = crop->rect;
> >>>>   
> >>>>
> >>>> base-commit: 39cd87c4eb2b893354f3b850f916353f2658ae6f

-- 
Regards,

Laurent Pinchart

Re: [PATCH] media: v4l2-subdev: Fix stream handling for crop API

[Sakari Ailus]

Moi,

On Tue, Apr 02, 2024 at 12:11:30PM +0300, Tomi Valkeinen wrote:
> On 02/04/2024 11:46, Sakari Ailus wrote:
> > On Tue, Apr 02, 2024 at 11:44:07AM +0300, Laurent Pinchart wrote:
> > > On Tue, Apr 02, 2024 at 08:20:22AM +0000, Sakari Ailus wrote:
> > > > Moi,
> > > > 
> > > > On Tue, Apr 02, 2024 at 02:37:25AM +0300, Laurent Pinchart wrote:
> > > > > When support for streams was added to the V4L2 subdev API, the
> > > > > v4l2_subdev_crop structure was extended with a stream field, but the
> > > > > field was not handled in the core code that translates the
> > > > > VIDIOC_SUBDEV_[GS]_CROP ioctls to the selection API. Fix it.
> > > > 
> > > > The field is indeed in the UAPI headers. But do we want to support the CROP
> > > > IOCTL for streams? Shouldn't the callers be using the [GS]_SELECTION
> > > > instead?
> > > 
> > > They should, but if the field is there, we should support it :-) The
> > > alternative is to remove it. It will cause failures in v4l2-compliance
> > > that we'll need to handle though.
> > 
> > I'd prefer to stick to selections here, this is new functionality so
> > [GS]_CROP support isn't required. I don't have a strong opinion on the
> > matter though.
> 
> Maybe it's easier to just support the stream field, instead of making
> [GS]_CROP the odd case which looks like it should support streams, but then
> doesn't...

It's an old IOCTL already replaced by the [GS]_SELECTION. I mainly write
kernel space software but overall I think it's better if we can provide a
single API for controlling cropping instead of two with similar
functionality, of which the user then should choose from.

It should be also documented in this context if we choose support
[GS]_CROP.

So I believe we have less work to do and have a better result if we just
drop the stream field there. :-) 

-- 
Terveisin,

Sakari Ailus

Re: [PATCH] media: v4l2-subdev: Fix stream handling for crop API

[Laurent Pinchart]

On Tue, Apr 02, 2024 at 03:23:03PM +0000, Sakari Ailus wrote:
> On Tue, Apr 02, 2024 at 12:11:30PM +0300, Tomi Valkeinen wrote:
> > On 02/04/2024 11:46, Sakari Ailus wrote:
> > > On Tue, Apr 02, 2024 at 11:44:07AM +0300, Laurent Pinchart wrote:
> > > > On Tue, Apr 02, 2024 at 08:20:22AM +0000, Sakari Ailus wrote:
> > > > > Moi,
> > > > > 
> > > > > On Tue, Apr 02, 2024 at 02:37:25AM +0300, Laurent Pinchart wrote:
> > > > > > When support for streams was added to the V4L2 subdev API, the
> > > > > > v4l2_subdev_crop structure was extended with a stream field, but the
> > > > > > field was not handled in the core code that translates the
> > > > > > VIDIOC_SUBDEV_[GS]_CROP ioctls to the selection API. Fix it.
> > > > > 
> > > > > The field is indeed in the UAPI headers. But do we want to support the CROP
> > > > > IOCTL for streams? Shouldn't the callers be using the [GS]_SELECTION
> > > > > instead?
> > > > 
> > > > They should, but if the field is there, we should support it :-) The
> > > > alternative is to remove it. It will cause failures in v4l2-compliance
> > > > that we'll need to handle though.
> > > 
> > > I'd prefer to stick to selections here, this is new functionality so
> > > [GS]_CROP support isn't required. I don't have a strong opinion on the
> > > matter though.
> > 
> > Maybe it's easier to just support the stream field, instead of making
> > [GS]_CROP the odd case which looks like it should support streams, but then
> > doesn't...
> 
> It's an old IOCTL already replaced by the [GS]_SELECTION. I mainly write
> kernel space software but overall I think it's better if we can provide a
> single API for controlling cropping instead of two with similar
> functionality, of which the user then should choose from.
> 
> It should be also documented in this context if we choose support
> [GS]_CROP.
> 
> So I believe we have less work to do and have a better result if we just
> drop the stream field there. :-) 

I tend to agree, even if that's only a slight preference. Tomi, if
you're fine with this, I'll update the patch.

-- 
Regards,

Laurent Pinchart

Re: [PATCH] media: v4l2-subdev: Fix stream handling for crop API

[Tomi Valkeinen]

On 02/04/2024 23:11, Laurent Pinchart wrote:
> On Tue, Apr 02, 2024 at 03:23:03PM +0000, Sakari Ailus wrote:
>> On Tue, Apr 02, 2024 at 12:11:30PM +0300, Tomi Valkeinen wrote:
>>> On 02/04/2024 11:46, Sakari Ailus wrote:
>>>> On Tue, Apr 02, 2024 at 11:44:07AM +0300, Laurent Pinchart wrote:
>>>>> On Tue, Apr 02, 2024 at 08:20:22AM +0000, Sakari Ailus wrote:
>>>>>> Moi,
>>>>>>
>>>>>> On Tue, Apr 02, 2024 at 02:37:25AM +0300, Laurent Pinchart wrote:
>>>>>>> When support for streams was added to the V4L2 subdev API, the
>>>>>>> v4l2_subdev_crop structure was extended with a stream field, but the
>>>>>>> field was not handled in the core code that translates the
>>>>>>> VIDIOC_SUBDEV_[GS]_CROP ioctls to the selection API. Fix it.
>>>>>>
>>>>>> The field is indeed in the UAPI headers. But do we want to support the CROP
>>>>>> IOCTL for streams? Shouldn't the callers be using the [GS]_SELECTION
>>>>>> instead?
>>>>>
>>>>> They should, but if the field is there, we should support it :-) The
>>>>> alternative is to remove it. It will cause failures in v4l2-compliance
>>>>> that we'll need to handle though.
>>>>
>>>> I'd prefer to stick to selections here, this is new functionality so
>>>> [GS]_CROP support isn't required. I don't have a strong opinion on the
>>>> matter though.
>>>
>>> Maybe it's easier to just support the stream field, instead of making
>>> [GS]_CROP the odd case which looks like it should support streams, but then
>>> doesn't...
>>
>> It's an old IOCTL already replaced by the [GS]_SELECTION. I mainly write
>> kernel space software but overall I think it's better if we can provide a
>> single API for controlling cropping instead of two with similar
>> functionality, of which the user then should choose from.
>>
>> It should be also documented in this context if we choose support
>> [GS]_CROP.
>>
>> So I believe we have less work to do and have a better result if we just
>> drop the stream field there. :-)
> 
> I tend to agree, even if that's only a slight preference. Tomi, if
> you're fine with this, I'll update the patch.

I'm fine with it. So we now should move the 'stream' field back to 
reserved, and add documentation saying that [GS]_CROP works differently 
than the other ioctls?

  Tomi

Re: [PATCH] media: v4l2-subdev: Fix stream handling for crop API

[Laurent Pinchart]

On Wed, Apr 03, 2024 at 09:51:01AM +0300, Tomi Valkeinen wrote:
> On 02/04/2024 23:11, Laurent Pinchart wrote:
> > On Tue, Apr 02, 2024 at 03:23:03PM +0000, Sakari Ailus wrote:
> >> On Tue, Apr 02, 2024 at 12:11:30PM +0300, Tomi Valkeinen wrote:
> >>> On 02/04/2024 11:46, Sakari Ailus wrote:
> >>>> On Tue, Apr 02, 2024 at 11:44:07AM +0300, Laurent Pinchart wrote:
> >>>>> On Tue, Apr 02, 2024 at 08:20:22AM +0000, Sakari Ailus wrote:
> >>>>>> Moi,
> >>>>>>
> >>>>>> On Tue, Apr 02, 2024 at 02:37:25AM +0300, Laurent Pinchart wrote:
> >>>>>>> When support for streams was added to the V4L2 subdev API, the
> >>>>>>> v4l2_subdev_crop structure was extended with a stream field, but the
> >>>>>>> field was not handled in the core code that translates the
> >>>>>>> VIDIOC_SUBDEV_[GS]_CROP ioctls to the selection API. Fix it.
> >>>>>>
> >>>>>> The field is indeed in the UAPI headers. But do we want to support the CROP
> >>>>>> IOCTL for streams? Shouldn't the callers be using the [GS]_SELECTION
> >>>>>> instead?
> >>>>>
> >>>>> They should, but if the field is there, we should support it :-) The
> >>>>> alternative is to remove it. It will cause failures in v4l2-compliance
> >>>>> that we'll need to handle though.
> >>>>
> >>>> I'd prefer to stick to selections here, this is new functionality so
> >>>> [GS]_CROP support isn't required. I don't have a strong opinion on the
> >>>> matter though.
> >>>
> >>> Maybe it's easier to just support the stream field, instead of making
> >>> [GS]_CROP the odd case which looks like it should support streams, but then
> >>> doesn't...
> >>
> >> It's an old IOCTL already replaced by the [GS]_SELECTION. I mainly write
> >> kernel space software but overall I think it's better if we can provide a
> >> single API for controlling cropping instead of two with similar
> >> functionality, of which the user then should choose from.
> >>
> >> It should be also documented in this context if we choose support
> >> [GS]_CROP.
> >>
> >> So I believe we have less work to do and have a better result if we just
> >> drop the stream field there. :-)
> > 
> > I tend to agree, even if that's only a slight preference. Tomi, if
> > you're fine with this, I'll update the patch.
> 
> I'm fine with it. So we now should move the 'stream' field back to 
> reserved, and add documentation saying that [GS]_CROP works differently 
> than the other ioctls?

That's the idea. I'll send patches.

-- 
Regards,

Laurent Pinchart