Shen MintaoandClaude Opus 5.5
c97644a43a
27af5ad added the CFG80211_VERSION make variable for OpenWrt builds that
use a newer mac80211 backport than the target kernel, but it is only
described in a Makefile comment. Document how to pass it from an OpenWrt
package Makefile, link the notes from the installation steps, and add
the build script and the kernel/backports combinations verified for
issue #94.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
2.8 KiB
Building with OpenWrt backports
OpenWrt's target kernel and wireless stack can have different versions. For example, issue #94 uses Linux 6.12.94 with backports 6.18.26 on OpenWrt 25.12.5. The Ubuntu build host's kernel version is not used to select these APIs.
Package Makefile
Pass CFG80211_VERSION=6.18.26 to the kernel make invocation for that
combination. Use the PKG_VERSION from your OpenWrt
package/kernel/mac80211/Makefile, in major.minor.patch format. Keep the
backports include paths and symbol versions from the same build:
NOSTDINC_FLAGS := \
$(KERNEL_NOSTDINC_FLAGS) \
-I$(STAGING_DIR)/usr/include/mac80211-backport/uapi \
-I$(STAGING_DIR)/usr/include/mac80211-backport \
-I$(STAGING_DIR)/usr/include/mac80211/uapi \
-I$(STAGING_DIR)/usr/include/mac80211 \
-include backport/backport.h
define Build/Compile
+$(KERNEL_MAKE) $(PKG_JOBS) \
M="$(PKG_BUILD_DIR)/drivers/aic8800" \
KBUILD_EXTRA_SYMBOLS="$(LINUX_DIR)/../symvers/mac80211.symvers" \
NOSTDINC_FLAGS="$(NOSTDINC_FLAGS)" \
CFG80211_VERSION=6.18.26 \
modules
endef
The package must depend on kmod-cfg80211 so its headers and symbol versions
are staged before this driver is built. Keep any additional dependencies,
firmware installation rules and module packaging rules your device needs.
Update the package's pinned source revision to one containing this fix, or
apply the fix as an OpenWrt package patch, then clean and rebuild the package:
make package/kernel/aic8800d80/clean
make package/kernel/aic8800d80/compile V=sc -j1
Changing CFG80211_VERSION alone does not update the driver source or the
wireless headers. The value must match the actual wireless stack; do not set
it to the host kernel version or redefine LINUX_VERSION_CODE.
Compatibility scope
The override selects the wireless API changes since Linux 6.12, including monitor-channel callbacks, radio/link arguments, radar notifications and newer cfg80211 callbacks. Timer, USB, memory-management and module namespace checks continue to use the target kernel version. Older target kernels with newer backports may need additional wireless API adaptations.
Leave CFG80211_VERSION unset when building against the kernel's own wireless
stack, as on a regular Ubuntu/Debian installation. The driver then uses the
kernel version as before. Hardware revision still determines whether to use
main or legacy-mcu1; a wireless API mismatch does not change that choice.
The feeds/Kconfig duplicate definitions and recursive dependencies also reported in issue #94 belong to the OpenWrt build configuration and require separate investigation.
See the build regression recipe for the tested kernel/backports combinations and a script to repeat the build.