[2.6 patch] let W1 select NET

[2.6 patch] let W1 select NET

[Adrian Bunk]

W1=y and Net=n fails with the following compile error:

<--  snip  -->

...
  LD      .tmp_vmlinux1
drivers/built-in.o(.text+0x5efa38): In function `w1_alloc_dev':
: undefined reference to `netlink_kernel_create'
drivers/built-in.o(.text+0x5efac1): In function `w1_alloc_dev':
: undefined reference to `sock_release'
drivers/built-in.o(.text+0x5efb31): In function `w1_free_dev':
: undefined reference to `sock_release'
drivers/built-in.o(.text+0x5f0014): In function `w1_netlink_send':
: undefined reference to `alloc_skb'
drivers/built-in.o(.text+0x5f00cd): In function `w1_netlink_send':
: undefined reference to `netlink_broadcast'
drivers/built-in.o(.text+0x5f0131): In function `w1_netlink_send':
: undefined reference to `skb_over_panic'
make: *** [.tmp_vmlinux1] Error 1

<--  snip  -->


The patch below fixes this issue by letting W1 select NET.


Signed-off-by: Adrian Bunk <bunk@fs.tum.de>

--- linux-2.6.8-rc4-mm1-full-3.4/drivers/w1/Kconfig.old	2004-08-13 12:00:05.000000000 +0200
+++ linux-2.6.8-rc4-mm1-full-3.4/drivers/w1/Kconfig	2004-08-13 12:11:31.000000000 +0200
@@ -2,6 +2,7 @@
 
 config W1
 	tristate "Dallas's 1-wire support"
+	select NET
 	---help---
 	  Dallas's 1-wire bus is usefull to connect slow 1-pin devices 
 	  such as iButtons and thermal sensors.

Re: [2.6 patch] let W1 select NET

[Evgeniy Polyakov]

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On Fri, 2004-08-13 at 14:17, Adrian Bunk wrote:
> W1=y and Net=n fails with the following compile error:
> 
> <--  snip  -->
> 
> ...
>   LD      .tmp_vmlinux1
> drivers/built-in.o(.text+0x5efa38): In function `w1_alloc_dev':
> : undefined reference to `netlink_kernel_create'
> drivers/built-in.o(.text+0x5efac1): In function `w1_alloc_dev':
> : undefined reference to `sock_release'
> drivers/built-in.o(.text+0x5efb31): In function `w1_free_dev':
> : undefined reference to `sock_release'
> drivers/built-in.o(.text+0x5f0014): In function `w1_netlink_send':
> : undefined reference to `alloc_skb'
> drivers/built-in.o(.text+0x5f00cd): In function `w1_netlink_send':
> : undefined reference to `netlink_broadcast'
> drivers/built-in.o(.text+0x5f0131): In function `w1_netlink_send':
> : undefined reference to `skb_over_panic'
> make: *** [.tmp_vmlinux1] Error 1
> 
> <--  snip  -->
> 
> 
> The patch below fixes this issue by letting W1 select NET.

Sure.
W1 requires netlink and thus CONFIG_NET.

Thank you.
I've applied your patch to my tree 
and will send it to GregKH -> Andrew Morton.

> 
> Signed-off-by: Adrian Bunk <bunk@fs.tum.de>
> 
> --- linux-2.6.8-rc4-mm1-full-3.4/drivers/w1/Kconfig.old	2004-08-13 12:00:05.000000000 +0200
> +++ linux-2.6.8-rc4-mm1-full-3.4/drivers/w1/Kconfig	2004-08-13 12:11:31.000000000 +0200
> @@ -2,6 +2,7 @@
>  
>  config W1
>  	tristate "Dallas's 1-wire support"
> +	select NET
>  	---help---
>  	  Dallas's 1-wire bus is usefull to connect slow 1-pin devices 
>  	  such as iButtons and thermal sensors.
-- 
	Evgeniy Polyakov ( s0mbre )

Crash is better than data corruption. -- Art Grabowski

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Re: [2.6 patch] let W1 select NET

[Roman Zippel]

Hi,

On Fri, 13 Aug 2004, Adrian Bunk wrote:

>  config W1
>  	tristate "Dallas's 1-wire support"
> +	select NET

What's wrong with a simple dependency?

bye, Roman

Re: [2.6 patch] let W1 select NET

[Evgeniy Polyakov]

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On Fri, 2004-08-13 at 14:32, Roman Zippel wrote:
> Hi,
> 
> On Fri, 13 Aug 2004, Adrian Bunk wrote:
> 
> >  config W1
> >  	tristate "Dallas's 1-wire support"
> > +	select NET
> 
> What's wrong with a simple dependency?

W1 requires NET, and thus depends on it.
If you _do_ want W1 then you _do_ need network and then NET must be
selected.

> 
> bye, Roman
-- 
	Evgeniy Polyakov ( s0mbre )

Crash is better than data corruption. -- Art Grabowski

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Re: [2.6 patch] let W1 select NET

[Adrian Bunk]

On Fri, Aug 13, 2004 at 12:32:55PM +0200, Roman Zippel wrote:

> Hi,

Hi Roman,

> On Fri, 13 Aug 2004, Adrian Bunk wrote:
> 
> >  config W1
> >  	tristate "Dallas's 1-wire support"
> > +	select NET
> 
> What's wrong with a simple dependency?

it's common practice to make it easier for people configuring the kernel 
to use select instead of depends in such cases.

It's also relatively safe since NET itself doesn't has any dependencies.

> bye, Roman

cu
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed

Re: [2.6 patch] let W1 select NET

[Roman Zippel]

Hi,

On Fri, 13 Aug 2004, Evgeniy Polyakov wrote:

> On Fri, 2004-08-13 at 14:32, Roman Zippel wrote:
> > Hi,
> > 
> > On Fri, 13 Aug 2004, Adrian Bunk wrote:
> > 
> > >  config W1
> > >  	tristate "Dallas's 1-wire support"
> > > +	select NET
> > 
> > What's wrong with a simple dependency?
> 
> W1 requires NET, and thus depends on it.
> If you _do_ want W1 then you _do_ need network and then NET must be
> selected.

A simple "depends on NET" does this as well, I see no reason to abuse 
select.

bye, Roman

Re: [2.6 patch] let W1 select NET

[Adrian Bunk]

On Fri, Aug 13, 2004 at 12:54:25PM +0200, Roman Zippel wrote:
> Hi,
> 
> On Fri, 13 Aug 2004, Evgeniy Polyakov wrote:
> 
> > On Fri, 2004-08-13 at 14:32, Roman Zippel wrote:
> > > Hi,
> > > 
> > > On Fri, 13 Aug 2004, Adrian Bunk wrote:
> > > 
> > > >  config W1
> > > >  	tristate "Dallas's 1-wire support"
> > > > +	select NET
> > > 
> > > What's wrong with a simple dependency?
> > 
> > W1 requires NET, and thus depends on it.
> > If you _do_ want W1 then you _do_ need network and then NET must be
> > selected.
> 
> A simple "depends on NET" does this as well, I see no reason to abuse 
> select.

In the case of NET the discussion is mostly hypothetically since nearly 
everyone has enabled NET.

But the similar case of USB_STORAGE selecting SCSI is an example where 
select is a big user-visible improvement over depends.

> bye, Roman

cu
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed

Re: [2.6 patch] let W1 select NET

[Evgeniy Polyakov]

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On Fri, 2004-08-13 at 14:54, Roman Zippel wrote:
> Hi,
> 
> On Fri, 13 Aug 2004, Evgeniy Polyakov wrote:
> 
> > On Fri, 2004-08-13 at 14:32, Roman Zippel wrote:
> > > Hi,
> > > 
> > > On Fri, 13 Aug 2004, Adrian Bunk wrote:
> > > 
> > > >  config W1
> > > >  	tristate "Dallas's 1-wire support"
> > > > +	select NET
> > > 
> > > What's wrong with a simple dependency?
> > 
> > W1 requires NET, and thus depends on it.
> > If you _do_ want W1 then you _do_ need network and then NET must be
> > selected.
> 
> A simple "depends on NET" does this as well, I see no reason to abuse 
> select.

I think it does it in reverse order:
if we have NET then we _may_ select W1, but if we _need_ W1 and do not
know upon what it depends?

> bye, Roman
-- 
	Evgeniy Polyakov ( s0mbre )

Crash is better than data corruption. -- Art Grabowski

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Re: [2.6 patch] let W1 select NET

[Roman Zippel]

Hi,

On Fri, 13 Aug 2004, Adrian Bunk wrote:

> > On Fri, 13 Aug 2004, Adrian Bunk wrote:
> > 
> > >  config W1
> > >  	tristate "Dallas's 1-wire support"
> > > +	select NET
> > 
> > What's wrong with a simple dependency?
> 
> it's common practice to make it easier for people configuring the kernel 
> to use select instead of depends in such cases.

select is the wrong tool for this. NET is usually enabled anyway, 
selecting it has no real advantage.
Please use normal dependency whereever possible and use select in such 
cases only as exception and with very good reason. Making kernel 
configuration easier for aunt Tillie is not such reason.

bye, Roman

Re: [2.6 patch] let W1 select NET

[Bernd Eckenfels]

In article <20040813110137.GY13377@fs.tum.de> you wrote:
> In the case of NET the discussion is mostly hypothetically since nearly 
> everyone has enabled NET.

Especially  in the case where it is unlikely that somebody is deselecting
NET, it makes more sense to depend on it, since IFF somebody deselects NET
(i.e. embedding) he wants to actually see which drivers are still available
(and she does not expect to see stil network drivers which reverse her
selection).

Greetings
Bernd
-- 
eckes privat - http://www.eckes.org/
Project Freefire - http://www.freefire.org/

Re: [2.6 patch] let W1 select NET

[Roman Zippel]

Hi,

On Fri, 13 Aug 2004, Adrian Bunk wrote:

> But the similar case of USB_STORAGE selecting SCSI is an example where 
> select is a big user-visible improvement over depends.

comment "USB storage requires SCSI"
	depends on SCSI=n

That's also user visible and doesn't confuse the user later, why he can't 
deselect SCSI.

Abusing select is really the wrong answer. What is needed is an improved 
user interface, which allows to search through the kconfig information or 
even can match hardware information to a driver and aids the user in 
selecting the required dependencies.
Keeping the kconfig database clean and making kernel configuration easier 
are really two separate problems and we shouldn't sacrifice the former for 
the latter.

bye, Roman

Re: [2.6 patch] let W1 select NET

[Russell King]

On Fri, Aug 13, 2004 at 01:01:37PM +0200, Adrian Bunk wrote:
> On Fri, Aug 13, 2004 at 12:54:25PM +0200, Roman Zippel wrote:
> > Hi,
> > 
> > On Fri, 13 Aug 2004, Evgeniy Polyakov wrote:
> > 
> > > On Fri, 2004-08-13 at 14:32, Roman Zippel wrote:
> > > > Hi,
> > > > 
> > > > On Fri, 13 Aug 2004, Adrian Bunk wrote:
> > > > 
> > > > >  config W1
> > > > >  	tristate "Dallas's 1-wire support"
> > > > > +	select NET
> > > > 
> > > > What's wrong with a simple dependency?
> > > 
> > > W1 requires NET, and thus depends on it.
> > > If you _do_ want W1 then you _do_ need network and then NET must be
> > > selected.
> > 
> > A simple "depends on NET" does this as well, I see no reason to abuse 
> > select.
> 
> In the case of NET the discussion is mostly hypothetically since nearly 
> everyone has enabled NET.

In which case, can we remove the user-visibility of CONFIG_NET and
instead make all the protocols automatically select it.

I find the over-use of "select" distasteful, and produces a counter-
intuitive configuration system.  I'll carry on complaining each time
I see a patch on LKML which introduces yet another over-use of this
feature without properly considering the consequences of doing so.

-- 
Russell King
 Linux kernel    2.6 ARM Linux   - http://www.arm.linux.org.uk/
 maintainer of:  2.6 PCMCIA      - http://pcmcia.arm.linux.org.uk/
                 2.6 Serial core

Re: [2.6 patch] let W1 select NET

[Adrian Bunk]

On Fri, Aug 13, 2004 at 02:11:28PM +0200, Roman Zippel wrote:

> Hi,

Hi Roman,

> On Fri, 13 Aug 2004, Adrian Bunk wrote:
> 
> > But the similar case of USB_STORAGE selecting SCSI is an example where 
> > select is a big user-visible improvement over depends.
> 
> comment "USB storage requires SCSI"
> 	depends on SCSI=n
> 
> That's also user visible and doesn't confuse the user later, why he can't 
> deselect SCSI.

that's exactly what we have in 2.4, and it's definitely worse that the 
select.

> Abusing select is really the wrong answer. What is needed is an improved 
> user interface, which allows to search through the kconfig information or 
> even can match hardware information to a driver and aids the user in 
> selecting the required dependencies.
> Keeping the kconfig database clean and making kernel configuration easier 
> are really two separate problems and we shouldn't sacrifice the former for 
> the latter.

Currently there's no better choice then "abusing select".

As soon as your improved user interface is included, I'm willing to help 
to evaluate which select's should be turned back into dependencies.

> bye, Roman

cu
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed

Re: [2.6 patch] let W1 select NET

[Cornelia Huck]

On Fri, 13 Aug 2004 12:54:12 +0200
Adrian Bunk <bunk@fs.tum.de> wrote:

> It's also relatively safe since NET itself doesn't has any
> dependencies.

Otherwise, this would be problematic. Consider the following:

config FOO
        bool "foo"
        select BAR

config BAR
        bool
        depends on BAZ

config BAZ
        bool
        default n

You can select FOO, which will select BAR. In your config, you'll end up with
CONFIG_FOO=y
CONFIG_BAR=y
# CONFIG_BAZ is not set

(similar result if you don't specify BAZ at all), which would get you into trouble. (I saw this while looking into what happens if s390 uses drivers/Kconfig, and got a headache why some stuff was selected by
allyesconfig that depended on pci).

Question: Is this a bug or a feature? If the latter, select should probably not be used on anything that has dependencies...

Regards,
Cornelia

Re: [2.6 patch] let W1 select NET

[Evgeniy Polyakov]

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On Fri, 2004-08-13 at 17:52, Cornelia Huck wrote:
> On Fri, 13 Aug 2004 12:54:12 +0200
> Adrian Bunk <bunk@fs.tum.de> wrote:
> 
> > It's also relatively safe since NET itself doesn't has any
> > dependencies.
> 
> Otherwise, this would be problematic. Consider the following:
> 
> config FOO
>         bool "foo"
>         select BAR
> 
> config BAR
>         bool
>         depends on BAZ
> 
> config BAZ
>         bool
>         default n
> 
> You can select FOO, which will select BAR. In your config, you'll end up with
> CONFIG_FOO=y
> CONFIG_BAR=y
> # CONFIG_BAZ is not set
> 
> (similar result if you don't specify BAZ at all), which would get you into trouble. (I saw this while looking into what happens if s390 uses drivers/Kconfig, and got a headache why some stuff was selected by
> allyesconfig that depended on pci).
> 
> Question: Is this a bug or a feature? If the latter, select should probably not be used on anything that has dependencies...

It is just not a good example.
In other words - it is bad config dependencies.
You just caught error.
Not very good example with depends:

config A
	depends on B
config B
	depends on C
config C
	depends on A

Just do not create wrong dependencies - although it sounds like "do not
create deadlocks".

> Regards,
> Cornelia
-- 
	Evgeniy Polyakov ( s0mbre )

Crash is better than data corruption. -- Art Grabowski

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Re: [2.6 patch] let W1 select NET

[Cornelia Huck]

On Fri, 13 Aug 2004 19:10:00 +0400
Evgeniy Polyakov <johnpol@2ka.mipt.ru> wrote:

> It is just not a good example.
> In other words - it is bad config dependencies.
> You just caught error.
> Not very good example with depends:
> 
> config A
> 	depends on B
> config B
> 	depends on C
> config C
> 	depends on A
> 
> Just do not create wrong dependencies - although it sounds like "do 
> not create deadlocks".

Hm, none too easy with configurations spread over multiple files :) - however, should select really be able to activate an option with unmet dependencies?

(and iirc, you are warned about circular dependencies?)

Regards,
Cornelia

Re: [2.6 patch] let W1 select NET

[Randy.Dunlap]

On Fri, 13 Aug 2004 14:11:28 +0200 (CEST) Roman Zippel wrote:

| Hi,
| 
| On Fri, 13 Aug 2004, Adrian Bunk wrote:
| 
| > But the similar case of USB_STORAGE selecting SCSI is an example where 
| > select is a big user-visible improvement over depends.
| 
| comment "USB storage requires SCSI"
| 	depends on SCSI=n
| 
| That's also user visible and doesn't confuse the user later, why he can't 
| deselect SCSI.

User-visible in xconfig (and gconfig?).  Not in menuconfig, right?
Maybe menuconfig's Help could also display dependency info...

| Abusing select is really the wrong answer. What is needed is an improved 
| user interface, which allows to search through the kconfig information or 
| even can match hardware information to a driver and aids the user in 
| selecting the required dependencies.

Nice idea.  So are there places where SELECT is the right thing to do,
i.e., it's required?  (examples, please)

| Keeping the kconfig database clean and making kernel configuration easier 
| are really two separate problems and we shouldn't sacrifice the former for 
| the latter.


--
~Randy

Re: [2.6 patch] let W1 select NET

[Evgeniy Polyakov]

On Fri, 13 Aug 2004 17:45:22 +0200
Cornelia Huck <kernel@cornelia-huck.de> wrote:

> On Fri, 13 Aug 2004 19:10:00 +0400
> Evgeniy Polyakov <johnpol@2ka.mipt.ru> wrote:
> 
> > It is just not a good example.
> > In other words - it is bad config dependencies.
> > You just caught error.
> > Not very good example with depends:
> > 
> > config A
> > 	depends on B
> > config B
> > 	depends on C
> > config C
> > 	depends on A
> > 
> > Just do not create wrong dependencies - although it sounds like "do 
> > not create deadlocks".
> 
> Hm, none too easy with configurations spread over multiple files :) -
> however, should select really be able to activate an option with unmet
> dependencies?

We have spinlock debugging, probably we need it in config parser too.
I think it is better to fix such bugs( or features), then hide them with
depend/select.
 
> (and iirc, you are warned about circular dependencies?)

I'm sure noone depends on w1 :)
 
> Regards,
> Cornelia


	Evgeniy Polyakov ( s0mbre )

Only failure makes us experts. -- Theo de Raadt

Re: [2.6 patch] let W1 select NET

[Roman Zippel]

Hi,

On Fri, 13 Aug 2004, Randy.Dunlap wrote:

> | Abusing select is really the wrong answer. What is needed is an improved 
> | user interface, which allows to search through the kconfig information or 
> | even can match hardware information to a driver and aids the user in 
> | selecting the required dependencies.
> 
> Nice idea.  So are there places where SELECT is the right thing to do,
> i.e., it's required?  (examples, please)

Select should be used for utility functions like CRC32, which often don't 
need their own prompt (except where some external module might need it, 
and a "default m" might suffice here).

bye, Roman

Re: [2.6 patch] let W1 select NET

[Miles Bader]

Russell King <rmk+lkml@arm.linux.org.uk> writes:
> In which case, can we remove the user-visibility of CONFIG_NET and
> instead make all the protocols automatically select it.

That would kind of annoying for cases where one really does want to
disable it though.  A very nice property of the current system is that
when one disables something like _NET, it removes a vast swath of other
options (which removes a lot of clutter from the interface), and _know_
you won't inadvertently drag in _NET by enabling something.

Conversely, the requirement that _NET be enabled to select various
network-related things isn't a problem from a user-interface point of
view, as it's `obvious' that one needs a network to use them (and the
config option to turn networking on is pretty starkly obvious when all
other networking options are removed).

This latter point in particular doesn't hold for some other
relationships (e.g. I seem to recall that various feature require SCSI
somewhat counter-intuitively, as they're not inherently related to it,
but rather have an implementation dependency on the kernel SCSI
infrastructure).

-Miles
-- 
Somebody has to do something, and it's just incredibly pathetic that it
has to be us.  -- Jerry Garcia