[libcamera-devel] [PATCH 08/11] licamera: v4l2_device: Support reading U8 array controls

[Laurent Pinchart]

And s/libcamera/libcamera/ in the subject line.

On Fri, Mar 20, 2020 at 11:30:27PM +0200, Laurent Pinchart wrote:
> On Mon, Mar 09, 2020 at 05:24:11PM +0100, Jacopo Mondi wrote:
> > Add support to retrieve the value of array controls of type
> > V4L2_CTRL_TYPE_U8.
> > 
> > Signed-off-by: Jacopo Mondi <jacopo at jmondi.org>
> > ---
> >  src/libcamera/v4l2_device.cpp | 26 ++++++++++++++++++++++++++
> >  1 file changed, 26 insertions(+)
> > 
> > diff --git a/src/libcamera/v4l2_device.cpp b/src/libcamera/v4l2_device.cpp
> > index 950e6286b84d..464df6a1fe18 100644
> > --- a/src/libcamera/v4l2_device.cpp
> > +++ b/src/libcamera/v4l2_device.cpp
> > @@ -185,6 +185,22 @@ int V4L2Device::getControls(ControlList *ctrls)
> >  			return -EINVAL;
> >  		}
> >  
> > +		const struct v4l2_query_ext_ctrl &info = ctrlsInfo_[id];
> > +		if (info.flags & V4L2_CTRL_FLAG_HAS_PAYLOAD) {
> > +			if (info.type != V4L2_CTRL_TYPE_U8) {
> > +				/*
> > +				 * \todo Fail loudly to notify support for
> > +				 * other array control types is not implemented.
> > +				 */
> > +				LOG(V4L2, Error) << "Unsupported type";
> > +				return -EINVAL;
> > +			}
> > +
> > +			size_t sizeBytes = info.elems * info.elem_size;
> > +			v4l2Ctrls[i].p_u8 = new uint8_t[sizeBytes];
> > +			v4l2Ctrls[i].size = sizeBytes;
> 
> Having to allocate extra memory here isn't very nice :-S I think that we
> should try to instead write directly in the ControlValue data,
> especially given that the updateControls() function should lose handling
> of the V4L2_CTRL_TYPE_U8 type as explained in the review of patch 07/11.
> I have a patch to implement this in ControlValue, I'll send it.
> 
> > +		}
> > +
> >  		v4l2Ctrls[i].id = id;
> >  		i++;
> >  	}
> > @@ -214,6 +230,16 @@ int V4L2Device::getControls(ControlList *ctrls)
> >  
> >  	updateControls(ctrls, v4l2Ctrls, count);
> >  
> > +	/* Release memory reserved for array controls. */
> > +	for (unsigned int i = 0; i < count; i++) {
> > +		unsigned int id = v4l2Ctrls[i].id;
> > +		const struct v4l2_query_ext_ctrl &info = ctrlsInfo_[id];
> > +
> > +		/* \todo Adjust to support more array control types. */
> > +		if (info.flags & V4L2_CTRL_FLAG_HAS_PAYLOAD)
> > +			delete[] v4l2Ctrls[i].p_u8;
> > +	}
> > +
> >  	return ret;
> >  }
> >  

-- 
Regards,

Laurent Pinchart