Re: ARM defconfig files

From: Russell King
Date: Thu Jun 03 2010 - 16:18:47 EST


On Thu, Jun 03, 2010 at 01:06:48PM -0700, Daniel Walker wrote:
> On Thu, 2010-06-03 at 20:57 +0100, Russell King wrote:
> > config MACH_HALIBUT
> > bool "Halibut Board (QCT SURF7201A)"
> > select I2C if STD_CONFIG
> > select I2C_WHATEVER if STD_CONFIG
> > ...
> >
> > That means if you enable STD_CONFIG, you'll get everything that's required
> > selected. If you then disable STD_CONFIG, I believe Kconfig leaves
> > everything that was selected as still being selected.
>
> I just did a little test, and it doesn't. Kconfig would un-select all
> the drivers, at least from my test.

That's because it knows what the original state of the symbol is.
Yes, that's a little undesirable for our behaviour - but it can be
worked around - by saving and restarting Kconfig.

Try this:

config STD_CONFIG
bool "Standard config"
default y

config DRIVER_A
tristate "Driver A"

config ARM
def_bool y
select DRIVER_A if STD_CONFIG

and in a new directory /path/to/kernel/scripts/kconfig/mconf test.conf
If you turn off STD_CONFIG immediately, it'll turn off DRIVER_A.
However, save out the config, and re-run mconf test.conf. You'll then
find that DRIVER_A remains set even when STD_CONFIG is turned off.

So, Kconfig does have the behaviour we desire but it's not directly
accessible.

Is it worth persuing? Will Linus accept this STD_CONFIG idea or did
his lack of reply to it indicate that he's not something he's willing
to entertain?

In any case, this is my last mail on the subject. I won't be replying
to mail for at least the next four days.

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