[Buildroot] [PATCH] [RFC] linux: add option to avoid kernel kconfig updates

[gustavo.zacarias at free-electrons.com]

From: Gustavo Zacarias <gustavo.zacarias at free-electrons.com>

Some packages require specific kernel options enabled to be of any use,
however when building a kernel with a specific configuration intended
for binary-only modules this can be counterproductive.

Add an option to disable this behaviour and leave the .config alone.

Signed-off-by: Gustavo Zacarias <gustavo.zacarias at free-electrons.com>
---
 linux/Config.in | 12 ++++++++++++
 linux/linux.mk  |  2 ++
 2 files changed, 14 insertions(+)

diff --git a/linux/Config.in b/linux/Config.in
index 99c8a0e..8c1b138 100644
--- a/linux/Config.in
+++ b/linux/Config.in
@@ -365,6 +365,18 @@ config BR2_LINUX_KERNEL_INSTALL_TARGET
 	  /boot if DTBs have been generated by the kernel build
 	  process.
 
+config BR2_LINUX_KERNEL_PACKAGES_ADJUST_CONFIG
+	bool "Adjust kernel configuration for package requirements"
+	default y
+	help
+	  Select this option if you want to allow packages to enable
+	  specific kernel options that are required for them to work
+	  properly.
+
+	  Normally you'd want this unless you're using precompiled
+	  binary-only modules that are tied to a specific kernel
+	  configuration via modversions.
+
 # Linux extensions
 source "linux/Config.ext.in"
 
diff --git a/linux/linux.mk b/linux/linux.mk
index 6c7ecfc..16eeb2c 100644
--- a/linux/linux.mk
+++ b/linux/linux.mk
@@ -176,6 +176,7 @@ LINUX_KCONFIG_FRAGMENT_FILES = $(call qstrip,$(BR2_LINUX_KERNEL_CONFIG_FRAGMENT_
 LINUX_KCONFIG_EDITORS = menuconfig xconfig gconfig nconfig
 LINUX_KCONFIG_OPTS = $(LINUX_MAKE_FLAGS)
 
+ifeq ($(BR2_LINUX_KERNEL_PACKAGES_ADJUST_CONFIG),y)
 define LINUX_KCONFIG_FIXUP_CMDS
 	$(if $(LINUX_NEEDS_MODULES),
 		$(call KCONFIG_ENABLE_OPT,CONFIG_MODULES,$(@D)/.config))
@@ -225,6 +226,7 @@ define LINUX_KCONFIG_FIXUP_CMDS
 	$(if $(BR2_LINUX_KERNEL_APPENDED_DTB),
 		$(call KCONFIG_ENABLE_OPT,CONFIG_ARM_APPENDED_DTB,$(@D)/.config))
 endef
+endif
 
 ifeq ($(BR2_LINUX_KERNEL_DTS_SUPPORT),y)
 ifeq ($(BR2_LINUX_KERNEL_DTB_IS_SELF_BUILT),)
-- 
2.4.10