Re: [PATCH 2/2] media: Don't hide any menu if "ancillary drivers autoselect" is enabled

[Chen-Yu Tsai <wens@kernel.org>]

On Fri, Jul 26, 2019 at 1:06 AM Ezequiel Garcia <ezequiel@collabora.com> wrote:
>
> On Thu, 2019-07-25 at 12:57 -0300, Mauro Carvalho Chehab wrote:
> > Em Mon, 15 Jul 2019 18:23:16 -0300
> > Ezequiel Garcia <ezequiel@collabora.com> escreveu:
> >
> > > Many users have been complaining about not being able to find
> > > certain menu options. One such example are camera sensor drivers
> > > (e.g IMX219, OV5645, etc) which are common on embedded platforms
> > > and not always ancillary devices.
> > >
> > > The problem with MEDIA_SUBDRV_AUTOSELECT seems to be related
> > > to the fact that it uses the "visible" kbuild syntax to hide
> > > entire group of drivers.
> > >
> > > This is not obvious and, as explained above, not always desired.
> > >
> > > To fix the problem, drop the "visible" and stop hiding any menu
> > > options. Users skilled enough to configure their kernel are expected
> > > to be skilled enough to know what (not) to configure anyway.
> > >
> > > Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
> > > ---
> > >  drivers/media/dvb-frontends/Kconfig | 1 -
> > >  drivers/media/i2c/Kconfig           | 1 -
> > >  drivers/media/spi/Kconfig           | 1 -
> > >  drivers/media/tuners/Kconfig        | 1 -
> > >  4 files changed, 4 deletions(-)
> > >
> > > diff --git a/drivers/media/dvb-frontends/Kconfig b/drivers/media/dvb-frontends/Kconfig
> > > index dc43749177df..2d1fea3bf546 100644
> > > --- a/drivers/media/dvb-frontends/Kconfig
> > > +++ b/drivers/media/dvb-frontends/Kconfig
> > > @@ -1,5 +1,4 @@
> > >  menu "Customise DVB Frontends"
> > > -   visible if !MEDIA_SUBDRV_AUTOSELECT || COMPILE_TEST || EXPERT
> > >
> > >  comment "Multistandard (satellite) frontends"
> > >     depends on DVB_CORE
> > > diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
> > > index 79ce9ec6fc1b..475072bb67d6 100644
> > > --- a/drivers/media/i2c/Kconfig
> > > +++ b/drivers/media/i2c/Kconfig
> > > @@ -23,7 +23,6 @@ config VIDEO_IR_I2C
> > >  #
> > >
> > >  menu "I2C Encoders, decoders, sensors and other helper chips"
> > > -   visible if !MEDIA_SUBDRV_AUTOSELECT || COMPILE_TEST || EXPERT
> >
> > Hmm... Hans picked this patch, but IMO it doesn't make sense
> > for PC consumer people to see the hundreds of extra options
> > that making those menus visible will produce.
> >
> > This was added because in the past we had lots of issues with
> > people desktop/laptop settings with all those things enabled.
> >
> > In any case, if the desktop/laptop user is smart enough to
> > go though it, he can simply disable MEDIA_SUBDRV_AUTOSELECT and
> > manually select what he wants, so I really miss the point of
> > making those stuff always visible.
> >
> > Now, from this patch's comments, it seems that you want this
> > to be visible if CONFIG_EMBEDDED. So, I won't complain if you
> > replace the changes on this patch to:
> >
> >       menu "foo"
> >           visible if !MEDIA_SUBDRV_AUTOSELECT || !EMBEDDED || COMPILE_TEST || EXPERT
> >
> > In other words, for the normal guy that just wants to build the
> > latest media stuff for his PC camera or TV device to work, he won't
> > need to dig into hundreds of things that won't make any difference
> > if he enables, except for making the Kernel bigger.
> >
>
> Well, I think the real value of MEDIA_SUBDRV_AUTOSELECT is the autoselection,
> not the hidden part. I'm really missing to see what hiding anything gives you.
>
> In other words, this option gets useful when driver authors select ancillary
> drivers such as:
>
> config VIDEO_USBVISION
>         tristate "USB video devices based on Nogatech NT1003/1004/1005"
>         depends on I2C && VIDEO_V4L2
>         select VIDEO_TUNER
>         select VIDEO_SAA711X if MEDIA_SUBDRV_AUTOSELECT
>
> What's so confusing about having these drivers visible? Compared to the
> rest of the zillion menu options, what's more confusing about seeing these?
>
> Now, while I would agree with EMBEDDED, the problem with that is that
> many "embedded" platforms don't enable EMBEDDED. So, it's not that useful.
>
> Finally, let me give an example of why hiding the menus is so bad.
> Normally, to enable a symbol, we use the search tool.
>
> Now, when MEDIA_SUBDRV_AUTOSELECT=y, the search tool will _not_ take you
> there and there's no indication why.

As someone who has done so in the past year, I agree it's confusing.
I had to dig through the Kconfig files to figure out which knobs to
turn to get the OV5640 option out. The description says "auto-selecting",
which does not equal hiding everything. You could still have drivers
auto-selected (or not) based on a Kconfig option without hiding things.

ChenYu