[RFC PATCH V4 0/4] media: platform: Add support for Face Detection (FD) on mt8183 SoC

[Jerry-ch Chen]

Hi Tomasz,

On Wed, 2020-07-01 at 01:19 +0800, Tomasz Figa wrote:
> Hi Jerry,
> 
> On Tue, Jun 30, 2020 at 10:10:53PM +0800, Jerry-ch Chen wrote:
> > Hi Tomasz,
> > 
> > On Thu, 2020-05-21 at 18:38 +0000, Tomasz Figa wrote:
> > > Hi Jerry,
> > > 
> > > On Wed, May 13, 2020 at 11:45:37PM +0200, Tomasz Figa wrote:
> > > > Hi Jerry,
> > > > 
> > > > On Fri, May 8, 2020 at 4:03 AM Jerry-ch Chen <Jerry-ch.Chen at mediatek.com> wrote:
> > > > >
> > > > > Hi Laurent, Tomasz, Matthias,
> > > > >
> > > > > gentle ping for this patch set,
> > > > > If no new comments, I would like to send a newer version.
> > > > >
> > > > 
> > > > Sorry, I still haven't had a chance to look at the series, so feel
> > > > free to send a new version and I will take a look at the new one.
> > > > 
> > > 
> > > Finally found some time to review the series. Again sorry for the delay
> > > and thanks for your patience.
> > > 
> > > Some general comments:
> > > 1) The metadata format FourCC should be added in a separate patch,
> > > together with documentation for it.
> > > 2) Control IDs, structs used by the userspace, etc. should be defined in
> > > a header under include/uapi/linux.
> > > 
> > > Please also check my replies to particular patches for further comments.
> > > 
> > > Best regards,
> > > Tomasz
> > 
> > Appreciate for your reply,
> > 
> > So far, I've locally created an uapi header:
> > include/uapi/linux/mtk_fd_40.h
> > which provides some values, control ids, and the definitions of
> > structures that would be needed by user of mtk_fd_40 driver.
> > In addition, I also provide a MACRO as example in comments that can
> > extract the struct member with bit length and offset
> > definitions(eliminate the bit-fields).
> > 
> > Also, I would like to rename struct fd_user_output with struct
> > mtk_fd_hw_result. I worry fd_user_output would be a confusing name.
> 
> The change sounds good to me.
> 
> > I will add them in a separate patch in next version.
> > 
> 
> Okay.
> 
> > I am still working on the documentation, which might be
> > Documentation/media/uapi/v4l/pixfmt-meta-mtk-fd-40.rst.
> > Refering the other pixfmt-*.rst files, I will try to provide the
> > flat-table of the metadata with the structure of the mtk_fd_hw_result.
> > 
> 
> Sounds good to me.
> 
> > I am confusing that should I remain the name with -40 in the tail of rst
> > file?
> 
> The header and documentation file names should match the driver name.  I
> just noticed there is some inconsistency in the naming, though. The
> driver seems to be located under drivers/media/platform/mtk-isp/fd, but
> the driver name in the platform driver struct and as reported by
> VIDIOC_QUERYCAP seems to be "mtk-fd-4.0". 

> Since we have many mtk-* drivers in the tree currently, I think it might
> make sense to consolidate them under drivers/media/platform/mediatek,
> similarly to drivers/media/platform/qcom or /rockchip. But it could be
> done later, as a follow-up.
> 
> My suggestion would be to place the driver under
> drivers/media/platform/mtk-fd-40 and also rename the related Kconfig
> symbol to include the _40 suffix.
> 
> What do you think?
> 

I Appreciate your comments,
Sorry for the late reply.

Would it be possible for me to replace the driver as drivers/media/platform/mtk_fd/mtk-fd-40?(Just like mtk-isp/isp_50)

> > Since I think the layout of metadata might be different in the future
> > mtk fd drivers. Maybe they create a new one or should they update the
> > rst file when they are upstreaming?
> > 
> 
> I think we'll decide what to do when that happens. Depending on whether
> there is more face detection hardware available, we might be able to
> migrate to standard controls and metadata buffer formats at that time.
> 
Ok.

> > Other comments are almost fixed, I will inform you by this mail thread
> > as soon as I finish the documentation of fd metadata format.
> 
> Okay, thanks.
> 
> Best regards,
> Tomasz

Thanks and Best Regards,
Jerry