Re:

From: Shuah Khan
Date: Fri Sep 13 2024 - 16:40:00 EST


On 9/13/24 11:11, David Hunter wrote:

Missing subject line for the cover-letter?

Date: Fri, 13 Sep 2024 11:52:16 -0400
Subject: [PATCH 0/7] linux-kbuild: fix: process configs set to "y"

An assumption made in this script is that the config options do not need
to be processed because they will simply be in the new config file. This
assumption is incorrect.

Process the config entries set to "y" because those config entries might
have dependencies set to "m". If a config entry is set to "m" and is not
loaded directly into the machine, the script will currently turn off
that config entry; however, if that turned off config entry is a
dependency for a "y" option. that means the config entry set to "y"
will also be turned off later when the conf executive file is called.

Here is a model of the problem (arrows show dependency):

Original config file
Config_1 (m) <-- Config_2 (y)

Config_1 is not loaded in this example, so it is turned off.
After scripts/kconfig/streamline_config.pl, but before scripts/kconfig/conf
Config_1 (n) <-- Config_2 (y)

After scripts/kconfig/conf
Config_1 (n) <-- Config_2 (n)


It should also be noted that any module in the dependency chain will
also be turned off, even if that module is loaded directly onto the
computer. Here is an example:

Original config file
Config_1 (m) <-- Config_2 (y) <-- Config_3 (m)

Config_3 will be loaded in this example.
After scripts/kconfig/streamline_config.pl, but before scripts/kconfig/conf
Config_1 (n) <-- Config_2 (y) <-- Config_3 (m)

After scripts/kconfig/conf
Config_1 (n) <-- Config_2 (n) <-- Config_3 (n)


I discovered this problem when I ran "make localmodconfig" on a generic
Ubuntu config file. Many hardware devices were not recognized once the
kernel was installed and booted. Another way to reproduced the error I
had is to run "make localmodconfig" twice. The standard error might display
warnings that certain modules should be selected but no config files are
turned on that select that module.

With the changes in this series patch, all modules are loaded properly
and all of the hardware is loaded when the kernel is installed and
booted.


David Hunter (7):
linux-kbuild: fix: config option can be bool
linux-kbuild: fix: missing variable operator
linux-kbuild: fix: ensure all defaults are tracked
linux-kbuild: fix: ensure selected configs were turned on in original
linux-kbuild: fix: implement choice for kconfigs
linux-kbuild: fix: configs with defaults do not need a prompt
linux-kbuild: fix: process config options set to "y"

scripts/kconfig/streamline_config.pl | 77 ++++++++++++++++++++++++----
1 file changed, 66 insertions(+), 11 deletions(-)