Re: [PATCH] [media] imx: csi: retain current field order and colorimetry setting as default

[Philipp Zabel]

On Thu, 2017-04-06 at 16:10 +0100, Russell King - ARM Linux wrote:
> On Thu, Apr 06, 2017 at 05:01:52PM +0200, Philipp Zabel wrote:
> > On Thu, 2017-04-06 at 15:05 +0100, Russell King - ARM Linux wrote:
> > > On Thu, Apr 06, 2017 at 03:55:29PM +0200, Philipp Zabel wrote:
> > > > +
> > > > +	/* Retain current field setting as default */
> > > > +	if (sdformat->format.field == V4L2_FIELD_ANY)
> > > > +		sdformat->format.field = fmt->field;
> > > > +
> > > > +	/* Retain current colorspace setting as default */
> > > > +	if (sdformat->format.colorspace == V4L2_COLORSPACE_DEFAULT) {
> > > > +		sdformat->format.colorspace = fmt->colorspace;
> > > > +		if (sdformat->format.xfer_func == V4L2_XFER_FUNC_DEFAULT)
> > > > +			sdformat->format.xfer_func = fmt->xfer_func;
> > > > +		if (sdformat->format.ycbcr_enc == V4L2_YCBCR_ENC_DEFAULT)
> > > > +			sdformat->format.ycbcr_enc = fmt->ycbcr_enc;
> > > > +		if (sdformat->format.quantization == V4L2_QUANTIZATION_DEFAULT)
> > > > +			sdformat->format.quantization = fmt->quantization;
> > > > +	} else {
> > > > +		if (sdformat->format.xfer_func == V4L2_XFER_FUNC_DEFAULT) {
> > > > +			sdformat->format.xfer_func =
> > > > +				V4L2_MAP_XFER_FUNC_DEFAULT(
> > > > +						sdformat->format.colorspace);
> > > > +		}
> > > > +		if (sdformat->format.ycbcr_enc == V4L2_YCBCR_ENC_DEFAULT) {
> > > > +			sdformat->format.ycbcr_enc =
> > > > +				V4L2_MAP_YCBCR_ENC_DEFAULT(
> > > > +						sdformat->format.colorspace);
> > > > +		}
> > > > +		if (sdformat->format.quantization == V4L2_QUANTIZATION_DEFAULT) {
> > > > +			sdformat->format.quantization =
> > > > +				V4L2_MAP_QUANTIZATION_DEFAULT(
> > > > +						cc->cs != IPUV3_COLORSPACE_YUV,
> > > > +						sdformat->format.colorspace,
> > > > +						sdformat->format.ycbcr_enc);
> > > > +		}
> > > > +	}
> > > 
> > > Would it make sense for this to be a helper function?
> > 
> > Quite possible, the next subdev that has to set frame_interval on both
> > pads manually because its upstream source pad doesn't suport
> > frame_interval might want to do the same.
> 
> Hmm.  I'm not sure I agree with this approach.  If a subdev hardware
> does not support any modification of the colourspace or field, then
> it should not be modifyable at the source pad - it should retain the
> propagated settings from the sink pad.

This new code is only relevant for the CSI_SINK_PAD.

> I thought I had already sent a patch doing exactly that.

Yes. Right above the modification there is a call to csi_try_fmt which
will already fix up sdformat->format for the source pads. So for the
CSI_SRC_PAD_DIRECT and CSI_SRC_PAD_IDMAC this should amount to a no-op.

If might be better to move this into a separate function and only call
it if sdformat->pad == CSI_SINK_PAD.

regards
Philipp