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

[Ezequiel Garcia <ezequiel@collabora.com>]

On Thu, 2019-07-25 at 23:09 -0300, Mauro Carvalho Chehab wrote:
> Em Thu, 25 Jul 2019 20:55:13 -0300
> Ezequiel Garcia <ezequiel@collabora.com> escreveu:
> 
> > On Thu, 2019-07-25 at 15:41 -0300, Mauro Carvalho Chehab wrote:
> > > Em Fri, 26 Jul 2019 01:29:58 +0800
> > > Chen-Yu Tsai <wens@kernel.org> escreveu:
> > >   
> > > > 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",  
> > > 
> > > Well, the text and/or the help message can be changed, if it is not
> > > clear enough, but this option was added because we had too many issues
> > > with users trying to build drivers for their devices without being
> > > able to do that, because selecting thousands of devices is something
> > > that an average PC user has troubles.
> > > 
> > > I'm all to improve it, provided that we don't make harder for non-devs
> > > to build the Kernel.
> > >   
> > 
> > I just recalled Buildroot made extensive use of comments,
> > so how about this instead:
> > 
> > From fdbb96242422823a6df59cf457ebd19f83e45ffe Mon Sep 17 00:00:00 2001
> > From: Ezequiel Garcia <ezequiel@collabora.com>
> > Date: Thu, 25 Jul 2019 20:45:07 -0300
> > Subject: [PATCH] media: Clarify how menus are hidden by SUBDRV_AUTOSELECT
> > 
> > Some users have been having a hard time finding certain menu
> > options. One such example are camera sensor drivers
> > (e.g IMX219, OV5645, etc) which are common on embedded
> > platforms and not really "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 it normally takes some time to
> > figure out.
> > 
> > To fix the problem, add a comment on each of hidden menus,
> > which should clarify what option is causing menus to be hidden.
> > 
> > Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
> > ---
> >  drivers/media/dvb-frontends/Kconfig | 3 +++
> >  drivers/media/i2c/Kconfig           | 3 +++
> >  drivers/media/spi/Kconfig           | 3 +++
> >  drivers/media/tuners/Kconfig        | 4 ++++
> >  4 files changed, 13 insertions(+)
> > 
> > diff --git a/drivers/media/dvb-frontends/Kconfig b/drivers/media/dvb-frontends/Kconfig
> > index dc43749177df..5e2ba9d03662 100644
> > --- a/drivers/media/dvb-frontends/Kconfig
> > +++ b/drivers/media/dvb-frontends/Kconfig
> > @@ -1,3 +1,6 @@
> > +comment "DVB Frontend drivers hidden by 'Autoselect ancillary drivers'"
> > +	depends on !(!MEDIA_SUBDRV_AUTOSELECT || COMPILE_TEST || EXPERT)
> > +
> >  menu "Customise DVB Frontends"
> >  	visible if !MEDIA_SUBDRV_AUTOSELECT || COMPILE_TEST || EXPERT
> 
> Makes sense to me.
> 
> Yet, it will keep repeating the same dependency logic everywhere.
> 
> Maybe we could have something like:
> 
> config MEDIA_SIMPLIFY_SELECT
> 	bool
> 	depends on !(!MEDIA_SUBDRV_AUTOSELECT || COMPILE_TEST || EXPERT)
> 	default y
> 
> (yeah, the name sucks - feel free to suggest a better name for
> the symbol)
> 
> and use it instead of keeping repeating the same if over and over.
> 

I'll cook something up.