Re: [RFC PATCH V0 7/7] [media] platform: mtk-isp: Add Mediatek ISP Pass 1 driver

Tomasz Figa
2019-03-21T03:49:01Z

On Tue, Mar 12, 2019 at 5:16 PM Jungo Lin <jungo.lin@mediatek.com> wrote:
>
> On Thu, 2019-03-07 at 19:04 +0900, Tomasz Figa wrote:
[snip]
> > > +struct mtk_cam_mem2mem2_device {
> > > + const char *name;
> > > + const char *model;
> >
> > For both of the fields above, they seem to be always
> > MTK_CAM_DEV_P1_NAME, so we can just use the macro directly whenever
> > needed. No need for this indirection.
> >
>
> OK. These two fields will be removed in next patch.
>
> > > + struct device *dev;
> > > + int num_nodes;
> > > + struct mtk_cam_dev_video_device *nodes;
> > > + const struct vb2_mem_ops *vb2_mem_ops;
> >
> > This is always "vb2_dma_contig_memops", so it can be used directly.
> >
>
> Ditto.
>
> > > + unsigned int buf_struct_size;
> >
> > This is always sizeof(struct mtk_cam_dev_buffer), so no need to save
> > it in the struct.
> >
>
> Ditto.
>
> > > + int streaming;
> > > + struct v4l2_device *v4l2_dev;
> > > + struct media_device *media_dev;
> >
> > These 2 fields are already in mtk_cam_dev which is a superclass of
> > this struct. One can just access them from there directly.
> >
>
> Ditto.
>
> > > + struct media_pipeline pipeline;
> > > + struct v4l2_subdev subdev;
> >
> > Could you remind me what was the media topology exposed by this
> > driver? This is already the second subdev I spotted in this patch,
> > which looks strange.
> >
>
>
> For sub-device design, we will remove the sub-device for CIO and keep
> only one sub-device for ISP driver in next patch. We will also provide
> the media topology in RFC v1 patch to clarify.
>
> > > + struct media_pad *subdev_pads;
> > > + struct v4l2_file_operations v4l2_file_ops;
> > > + const struct file_operations fops;
> > > +};
> >
> > Given most of the comments above, it looks like the remaining useful
> > fields in this struct could be just moved to mtk_cam_dev, without the
> > need for this separate struct.
> >
>
> This is the final revision for these two structures.
> Do you suggest to merge it to simplify?
>
> struct mtk_cam_mem2mem2_device {
> struct mtk_cam_video_device *nodes;
> struct media_pipeline pipeline;
> struct v4l2_subdev subdev;
> struct media_pad *subdev_pads;
> };
>
> struct mtk_cam_dev {
> struct platform_device *pdev;
> struct mtk_cam_video_device mem2mem2_nodes[MTK_CAM_DEV_NODE_MAX];
> struct mtk_cam_mem2mem2_device mem2mem2;
> struct mtk_cam_io_connection cio;
> struct v4l2_device v4l2_dev;
> struct media_device media_dev;
> struct mtk_cam_ctx ctx;
> struct v4l2_async_notifier notifier;
> };
>

I feel like there is not much benefit in having this split. Similarly,
I'm not sure if there is a reason to have separate structs for
mtk_cam_io_connection and mtk_cam_ctx.

(Sorry, missed this one in previous reply.)

Best regards,
Tomasz