[PATCH] linux-module: make sure out-of-tree modules win over built-in

[Henning Schild <henning.schild@siemens.com>]

If we built an out of tree module that happens to be already part of the
kernel, we want to make sure depmod prefers the external one. In order
to do so simply include a config file into every module package, by
default using the kernels default INSTALL_MOD_DIR which is "extra".

Should there be multiple modules using different such directories, all
recipes should set INSTALL_MOD_DIR listing them all in the desired
order. That interface for multiple such very special modules is not nice
but since they are pretty special it might be just good enough.

Reported-by: Pingfang Liao <Pingfang.Liao@siemens.com>
Signed-off-by: Henning Schild <henning.schild@siemens.com>
---
 meta/recipes-kernel/linux-module/files/debian/rules.tmpl | 1 +
 meta/recipes-kernel/linux-module/module.inc              | 3 +++
 2 files changed, 4 insertions(+)

diff --git a/meta/recipes-kernel/linux-module/files/debian/rules.tmpl b/meta/recipes-kernel/linux-module/files/debian/rules.tmpl
index d3bd7dc30f21..abd3c88fac7e 100755
--- a/meta/recipes-kernel/linux-module/files/debian/rules.tmpl
+++ b/meta/recipes-kernel/linux-module/files/debian/rules.tmpl
@@ -55,6 +55,7 @@ override_dh_auto_build:
 
 override_dh_auto_install:
 	$(MAKE) -C $(KDIR) M=$(PWD) INSTALL_MOD_PATH=$(PWD)/debian/${PN} modules_install
+	install -D -m 0644 $(PWD)/debian/${PN}.conf $(PWD)/debian/${PN}/usr/lib/depmod.d/${PN}.conf
 
 %:
 	CFLAGS= LDFLAGS= dh $@ --parallel
diff --git a/meta/recipes-kernel/linux-module/module.inc b/meta/recipes-kernel/linux-module/module.inc
index b20ec32ae20a..475e7aef05ea 100644
--- a/meta/recipes-kernel/linux-module/module.inc
+++ b/meta/recipes-kernel/linux-module/module.inc
@@ -29,9 +29,12 @@ TEMPLATE_FILES = "debian/control.tmpl \
                   debian/rules.tmpl"
 TEMPLATE_VARS += "KERNEL_NAME KERNEL_TYPE KERNEL_IMAGE_PKG KERNEL_HEADERS_PKG DEBIAN_BUILD_DEPENDS PN"
 
+INSTALL_MOD_DIR ?= "extra"
+
 do_prepare_build() {
     cp -r ${WORKDIR}/debian ${S}/
 
+    echo "search ${INSTALL_MOD_DIR} built-in" > ${S}/debian/${PN}.conf
     for module in ${AUTOLOAD}; do
         echo "echo $module >> /etc/modules" >> ${S}/debian/postinst
     done
-- 
2.35.1