[libcamera-devel] [PATCH] Revert "libcamera: V4L2Device: Remove the controls order assumption in updateControls()"

[Jacopo Mondi]

Hi Laurent,

On Tue, May 25, 2021 at 11:55:28AM +0300, Laurent Pinchart wrote:
> This reverts commit 34bee5e84ecba01e0ded5cacbc46c277c5a0edba.
>
> The commit introduced a breakage in the master branch, reported by
> linux-surface users already. Let's revert it while discussing the
> propert fix.

I see a potential fix on the list but for now let's unblock users fast
Acked-by: Jacopo Mondi <jacopo at jmondi.org>

Thanks
   j

>
> Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> ---
>  src/libcamera/v4l2_device.cpp | 26 +++++++++++++++++++-------
>  1 file changed, 19 insertions(+), 7 deletions(-)
>
> diff --git a/src/libcamera/v4l2_device.cpp b/src/libcamera/v4l2_device.cpp
> index 7f7e5b8fdf09..caafbc2d16bb 100644
> --- a/src/libcamera/v4l2_device.cpp
> +++ b/src/libcamera/v4l2_device.cpp
> @@ -244,6 +244,12 @@ ControlList V4L2Device::getControls(const std::vector<uint32_t> &ids)
>
>  	ControlList ctrls{ controls_ };
>
> +	/*
> +	 * Start by filling the ControlList. This can't be combined with filling
> +	 * v4l2Ctrls, as updateControls() relies on both containers having the
> +	 * same order, and the control list is based on a map, which is not
> +	 * sorted by insertion order.
> +	 */
>  	for (uint32_t id : ids) {
>  		const auto iter = controls_.find(id);
>  		if (iter == controls_.end()) {
> @@ -617,13 +623,19 @@ void V4L2Device::updateControlInfo()
>  void V4L2Device::updateControls(ControlList *ctrls,
>  				Span<const v4l2_ext_control> v4l2Ctrls)
>  {
> -	for (const v4l2_ext_control &v4l2Ctrl : v4l2Ctrls) {
> -		const unsigned int id = v4l2Ctrl.id;
> +	unsigned int i = 0;
> +	for (auto &ctrl : *ctrls) {
> +		if (i == v4l2Ctrls.size())
> +			break;
>
> -		ControlValue value = ctrls->get(id);
> -		switch (value.type()) {
> +		const struct v4l2_ext_control *v4l2Ctrl = &v4l2Ctrls[i];
> +		unsigned int id = ctrl.first;
> +		ControlValue &value = ctrl.second;
> +
> +		const auto iter = controls_.find(id);
> +		switch (iter->first->type()) {
>  		case ControlTypeInteger64:
> -			value.set<int64_t>(v4l2Ctrl.value64);
> +			value.set<int64_t>(v4l2Ctrl->value64);
>  			break;
>
>  		case ControlTypeByte:
> @@ -638,11 +650,11 @@ void V4L2Device::updateControls(ControlList *ctrls,
>  			 * \todo To be changed when support for string controls
>  			 * will be added.
>  			 */
> -			value.set<int32_t>(v4l2Ctrl.value);
> +			value.set<int32_t>(v4l2Ctrl->value);
>  			break;
>  		}
>
> -		ctrls->set(id, value);
> +		i++;
>  	}
>  }
>
> --
> Regards,
>
> Laurent Pinchart
>