Cannot easily set CONFIG_WIRELESS_EXT in kernel 3.0 build

Cannot easily set CONFIG_WIRELESS_EXT in kernel 3.0 build

[Pavel Ivanov]

Hi,

I've tried to build and install kernel 3.0. The standard Ubuntu
configuration worked very well. But after I ran 'make localmodconfig',
rebuilt and rebooted my wireless didn't work. After some investigation
I've found that option CONFIG_WIRELESS_EXT is no longer set in .config
file. But no matter how I tried to include it in .config file it was
automatically deleted by 'make oldconfig' and again kernel compiled
without it. Then I've found that if I include in the build some
(completely unnecessary to me) wireless module which has 'select
WIRELESS_EXT' in its Kconfig then it stays in .config file and
resulting kernel works very well with my WiFi network. In fact even if
I add 'select WIRELESS_EXT' to Kconfig of the driver for my wireless
card (ath9k) everything works as well.

I'd think that such behavior is a bug, although I don't know on which
side. Either on the side of wireless drivers which all have to have
'select WIRELESS_EXT' in their Kconfig files or on the side of kbuild
system which doesn't allow me to set CONFIG_WIRELESS_EXT unless some
driver requires it. Interestingly enough requiring WIRELESS_EXT works
only with drivers, because I've tried to add CONFIG_LIBIPW (it
requires WIRELESS_EXT too) but it was automatically deleted from
.config file along with CONFIG_WIRELESS_EXT. So I couldn't include
only this library.

Could you tell me if this is indeed a bug or am I missing something here?
I'm not subscribed to the lists so please add me in CC.


Pavel

Re: Cannot easily set CONFIG_WIRELESS_EXT in kernel 3.0 build

[Michal Marek]

On 9.8.2011 17:04, Pavel Ivanov wrote:
> I'd think that such behavior is a bug, although I don't know on which
> side. Either on the side of wireless drivers which all have to have
> 'select WIRELESS_EXT' in their Kconfig files or on the side of kbuild
> system which doesn't allow me to set CONFIG_WIRELESS_EXT unless some
> driver requires it. Interestingly enough requiring WIRELESS_EXT works
> only with drivers, because I've tried to add CONFIG_LIBIPW (it
> requires WIRELESS_EXT too)

Both WIRELESS_EXT and LIBIPW are symbols without prompt, so they cannot
be selected by the user directly. Drivers that need CONFIG_WIRELESS_EXT
have to select it.

Michal

Re: Cannot easily set CONFIG_WIRELESS_EXT in kernel 3.0 build

[Arnaud Lacombe]

Hi,

On Tue, Aug 9, 2011 at 11:04 AM, Pavel Ivanov <paivanof@gmail.com> wrote:
> Hi,
>
> I've tried to build and install kernel 3.0. The standard Ubuntu
> configuration worked very well. But after I ran 'make localmodconfig',
> rebuilt and rebooted my wireless didn't work. After some investigation
> I've found that option CONFIG_WIRELESS_EXT is no longer set in .config
> file.
what is the ubuntu kernel version ?

> But no matter how I tried to include it in .config file it was
> automatically deleted by 'make oldconfig' and again kernel compiled
> without it.
well, .config is not meant to be edited manually. It is written at the
top of the file:

# Automatically generated file; DO NOT EDIT.

> Then I've found that if I include in the build some
> (completely unnecessary to me) wireless module which has 'select
> WIRELESS_EXT' in its Kconfig then it stays in .config file and
> resulting kernel works very well with my WiFi network.
>
expected behavior.

> In fact even if
> I add 'select WIRELESS_EXT' to Kconfig of the driver for my wireless
> card (ath9k) everything works as well.
>
did you look at ubuntu kernel sources to see if the Kconfig entry
ath9k driver had been changed to 'select WIRELESS_EXT' ? What may be
more likely is that ubuntu is building a bundle of driver, and one of
them include WIRELESS_EXT.

> I'd think that such behavior is a bug, although I don't know on which
> side. Either on the side of wireless drivers which all have to have
> 'select WIRELESS_EXT' in their Kconfig files
From what you describe, I'd say yes.

> or on the side of kbuild
> system which doesn't allow me to set CONFIG_WIRELESS_EXT unless some
> driver requires it. Interestingly enough requiring WIRELESS_EXT works
> only with drivers, because I've tried to add CONFIG_LIBIPW (it
> requires WIRELESS_EXT too) but it was automatically deleted from
> .config file along with CONFIG_WIRELESS_EXT. So I couldn't include
> only this library.
>
as Michal pointed out, that's the intended behavior.

Could you generate a patch for the change you made to make your
adapter works and send them to the wireless folks ? They are likely to
be more aware of the various requirement and inter-dependency of the
subsystem.

Thanks,
 - Arnaud

> Could you tell me if this is indeed a bug or am I missing something here?
> I'm not subscribed to the lists so please add me in CC.
>
>
> Pavel
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>

Re: Cannot easily set CONFIG_WIRELESS_EXT in kernel 3.0 build

[Pavel Ivanov]

Hi, Arnaud.

>> I've tried to build and install kernel 3.0. The standard Ubuntu
>> configuration worked very well. But after I ran 'make localmodconfig',
>> rebuilt and rebooted my wireless didn't work. After some investigation
>> I've found that option CONFIG_WIRELESS_EXT is no longer set in .config
>> file.
> what is the ubuntu kernel version ?

Ubuntu's version is 2.6.38.11-generic.

>> But no matter how I tried to include it in .config file it was
>> automatically deleted by 'make oldconfig' and again kernel compiled
>> without it.
> well, .config is not meant to be edited manually. It is written at the
> top of the file:
>
> # Automatically generated file; DO NOT EDIT.

Well, then how am I expected to manually change configuration
parameters without running any automated program? Manual editing of
.config worked (well, except some automatic changes which I've already
got used to). Should I edit some other file instead?

>> In fact even if
>> I add 'select WIRELESS_EXT' to Kconfig of the driver for my wireless
>> card (ath9k) everything works as well.
>>
> did you look at ubuntu kernel sources to see if the Kconfig entry
> ath9k driver had been changed to 'select WIRELESS_EXT' ? What may be
> more likely is that ubuntu is building a bundle of driver, and one of
> them include WIRELESS_EXT.

I didn't look at Ubuntu sources yet but I've just assumed the same -
as some of compiled drivers include WIRELESS_EXT everything works with
any driver.

> Could you generate a patch for the change you made to make your
> adapter works and send them to the wireless folks ? They are likely to
> be more aware of the various requirement and inter-dependency of the
> subsystem.

Will do, thanks.

Pavel