Re: [PATCH v2 5/9] media: staging: rkisp1: add a pointer to rkisp1_device from struct rkisp1_isp

[Dafna Hirschfeld <dafna.hirschfeld@xxxxxxxxxxxxx>]

Hi,

On 20.07.20 21:25, Helen Koike wrote:
> On 7/18/20 11:59 AM, Dafna Hirschfeld wrote:
> > The code in rkisp1-isp.c requires access to struct 'rkisp1_device'
> > in several places. It access it using the 'container_of' macro.
> > This patch adds a pointer to 'rkisp1_device' in struct 'rkisp1_isp'
> > to simplify the access.
>
> What is wrong with container_of?

I remember Laurent suggested it a while ago.
I also feel container_of is a bit cumbersome and other entities already have a pointer to rkisp1_device.

Thanks,
Dafna

> I usually prefer moving to container_of then the other way around, since this avoid a new field
> in the struct, and also avoid the requirements of keeping the pointer in sync.
>
> Thanks
> Helen
>
> > Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@xxxxxxxxxxxxx>
> > ---
> >   drivers/staging/media/rkisp1/rkisp1-common.h |  1 +
> >   drivers/staging/media/rkisp1/rkisp1-isp.c    | 12 +++++-------
> >   2 files changed, 6 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/staging/media/rkisp1/rkisp1-common.h b/drivers/staging/media/rkisp1/rkisp1-common.h
> > index e54793d13c3d..893caa9df891 100644
> > --- a/drivers/staging/media/rkisp1/rkisp1-common.h
> > +++ b/drivers/staging/media/rkisp1/rkisp1-common.h
> > @@ -106,6 +106,7 @@ struct rkisp1_sensor_async {
> >    */
> >   struct rkisp1_isp {
> >   	struct v4l2_subdev sd;
> > +	struct rkisp1_device *rkisp1;
> >   	struct media_pad pads[RKISP1_ISP_PAD_MAX];
> >   	struct v4l2_subdev_pad_config pad_cfg[RKISP1_ISP_PAD_MAX];
> >   	const struct rkisp1_isp_mbus_info *sink_fmt;
> > diff --git a/drivers/staging/media/rkisp1/rkisp1-isp.c b/drivers/staging/media/rkisp1/rkisp1-isp.c
> > index 6ec1e9816e9f..b2131aea5488 100644
> > --- a/drivers/staging/media/rkisp1/rkisp1-isp.c
> > +++ b/drivers/staging/media/rkisp1/rkisp1-isp.c
> > @@ -836,9 +836,8 @@ static int rkisp1_isp_set_selection(struct v4l2_subdev *sd,
> >   				    struct v4l2_subdev_pad_config *cfg,
> >   				    struct v4l2_subdev_selection *sel)
> >   {
> > -	struct rkisp1_device *rkisp1 =
> > -		container_of(sd->v4l2_dev, struct rkisp1_device, v4l2_dev);
> >   	struct rkisp1_isp *isp = container_of(sd, struct rkisp1_isp, sd);
> > +	struct rkisp1_device *rkisp1 = isp->rkisp1;
> >   	int ret = 0;
> >   
> >   	if (sel->target != V4L2_SEL_TGT_CROP)
> > @@ -883,8 +882,7 @@ static const struct v4l2_subdev_pad_ops rkisp1_isp_pad_ops = {
> >   static int rkisp1_mipi_csi2_start(struct rkisp1_isp *isp,
> >   				  struct rkisp1_sensor_async *sensor)
> >   {
> > -	struct rkisp1_device *rkisp1 =
> > -		container_of(isp->sd.v4l2_dev, struct rkisp1_device, v4l2_dev);
> > +	struct rkisp1_device *rkisp1 = isp->rkisp1;
> >   	union phy_configure_opts opts;
> >   	struct phy_configure_opts_mipi_dphy *cfg = &opts.mipi_dphy;
> >   	s64 pixel_clock;
> > @@ -916,9 +914,8 @@ static void rkisp1_mipi_csi2_stop(struct rkisp1_sensor_async *sensor)
> >   
> >   static int rkisp1_isp_s_stream(struct v4l2_subdev *sd, int enable)
> >   {
> > -	struct rkisp1_device *rkisp1 =
> > -		container_of(sd->v4l2_dev, struct rkisp1_device, v4l2_dev);
> > -	struct rkisp1_isp *isp = &rkisp1->isp;
> > +	struct rkisp1_isp *isp = container_of(sd, struct rkisp1_isp, sd);
> > +	struct rkisp1_device *rkisp1 = isp->rkisp1;
> >   	struct v4l2_subdev *sensor_sd;
> >   	int ret = 0;
> >   
> > @@ -997,6 +994,7 @@ int rkisp1_isp_register(struct rkisp1_device *rkisp1,
> >   	struct v4l2_subdev *sd = &isp->sd;
> >   	int ret;
> >   
> > +	isp->rkisp1 = rkisp1;
> >   	v4l2_subdev_init(sd, &rkisp1_isp_ops);
> >   	sd->flags |= V4L2_SUBDEV_FL_HAS_DEVNODE | V4L2_SUBDEV_FL_HAS_EVENTS;
> >   	sd->entity.ops = &rkisp1_isp_media_ops;