A bug was reported that caused localmodconfig to not keep all the
dependencies of ATH9K. This was caused by the kconfig file:

In drivers/net/wireless/ath/Kconfig:

---
if ATH_CARDS

config ATH_DEBUG
        bool "Atheros wireless debugging"
        ---help---
          Say Y, if you want to debug atheros wireless drivers.
          Right now only ath9k makes use of this.

source "drivers/net/wireless/ath/ath5k/Kconfig"
source "drivers/net/wireless/ath/ath9k/Kconfig"
source "drivers/net/wireless/ath/carl9170/Kconfig"
source "drivers/net/wireless/ath/ath6kl/Kconfig"
source "drivers/net/wireless/ath/ar5523/Kconfig"
source "drivers/net/wireless/ath/wil6210/Kconfig"

endif
---

The current way kconfig works, it processes new source files after the
first file is completed. It creates an array of new source config files
and when the one file is finished, it continues with the next file.

Unfortunately, this means that it loses the fact that the source file is
within an "if" statement, and this means that each of these source file's
configs will not have the proper dependencies set.

As ATH9K requires ATH_CARDS set, the localmodconfig did not see that
dependency, and did not enable ATH_CARDS. When the oldconfig was run, it
forced ATH9K to be disabled.

Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1304291022320.9234@oneiric

Cc: stable@vger.kernel.org # 3.8+
Reported-by: Robert P. J. Day <rpjday@crashcourse.ca>
Tested-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

When a config for a module is added to the list to save in the final
config file, add a print to show what dependencies are used. This is
useful to debug when a config is disabled by the make oldconfig after
localmodconfig is finished.

This print only appears if the environment variable LOCALMODCONFIG_DEBUG
is defined.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

The kbuild target 'localyesconfig' has been same as 'localmodconfig'
since the commit 50bce3e "kconfig/streamline_config.pl: merge
local{mod,yes}config". The commit expects this script generates
different configure depending on target, but it was not yet implemented.

So I added code that sets to 'yes' when target is 'localyesconfig'.

Link: http://lkml.kernel.org/r/1349101470-12243-1-git-send-email-yuta.and@gmail.com

Cc: stable@vger.kernel.org # v3.2
Cc: linux-kbuild@vger.kernel.org
Signed-off-by: Yuta Ando <yuta.and@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@rostedt.homelinux.com>

perlcritic complains about $kconfig being reused in the foreach loop
at the end of read_kconfig.  Change it to a my variable.

Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

Convert remaining open calls to use the perl's preferred 3 parameter
open.

Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

Change find_config function to read_config.  It now finds the config,
reads the config into an array, and returns the array.  This makes it
a little cleaner and changes the open to use perl's 3 option open.

Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

Running streamline_config.pl as it's shown it in the comment header,
you will get a warning about $ksource being uninitialized.  This is
because $ksource is set to ARGV[0], but the examples don't require any
arguments.  Fix by setting ksource to . if no ARGV[0] is given.

Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

If the environment variable LOCALMODCONFIG_DEBUG is set, then debug output
will appear in the make localmodconfig. This will simplify debugging what
people get with their output, as I can just tell people to do:

  LOCALMODCONFIG_DEBUG=1 make localmodconfig 2>out.txt

and have them send me the out.txt. I'll be able to see why things are not
working as they think it should be.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

There are some cases that a required module does not have a prompt
and needs to have another module enabled that selects it to be set.
As localmodconfig is conservative and tries to make the minimum config
without breaking the user's kernel, or keeping the user from using
devices that were loaded when the lsmod was done, all modules that
select this module will also be enabled.

If you needed module A, but module A did not have a prompt but needed
module B to be selected, localmodconfig would make sure B was still
enabled. If not only B selected A, but C, D, E, F, and G also
selected A, then all of those would also be included, as well as the
modules they depend on. This ballooned the number of configs that
localmodconfig would keep.

The fix here is to process the depends first, and then record those
configs that did not have a prompt and needed to be selected.
After the depends are done, check what configs are needed to select
the configs in the list, and if a config that selects it is already
set, then we don't need to do anything else.

If no config that selects the config is set, then just pick one and
try again.

This change brought down the number of selected modules from 290
to 67! Both before and after were run against a config that had 3095
modules enabled.

Tested-by: John David Yost <johnyost@ptd.net> # AlleyTrotter
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

Read in the entire config file. If there's a config that we depend on
that happens to be in the core set (not a module) then we do not need
to process it as a module.

Currently, we follow the entire depend and selects even if they
are enabled as core and not modules. By checking to make sure that we
only look at modules we can drop the count a little.

From one of my tests, localmodconfig went from taking 3095 set modules
down to 356 before this patch, and down to 290 modules after the change.

Tested-by: John David Yost <johnyost@ptd.net> # AlleyTrotter
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>