(one more note before i head out for canada day). i have a script that identified references to undefined CONFIG_* variables in Makefiles, but the number of those is so tiny (three) that i'll just list them here: ===== IWLMVM_AX_SOFTAP_TESTMODE ./drivers/net/wireless/intel/iwlwifi/mld/Makefile:iwlmld-$(CONFIG_IWLMVM_AX_SOFTAP_TESTMODE) += ax-softap-testmode.o ===== IWL_VENDOR_CMDS ./drivers/net/wireless/intel/iwlwifi/mld/Makefile:iwlmld-$(CONFIG_IWL_VENDOR_CMDS) += vendor-cmd.o ===== SENSORS_SBRMI ./drivers/hwmon/Makefile:obj-$(CONFIG_SENSORS_SBRMI) += sbrmi.o in the three Makefiles above, you can see references to "CONFIG_" variables that do not appear to be be defined anywhere in the kernel tree, so anyone interested is invited to examine what's happening in each case and how to clean it up. for that last case, i checked the Git log and if you run: $ git show e1565867640506166b6c4182dec9ee955492d003 that's the commit that deletes the definition: config SENSORS_SBRMI so you can do with that what you will; that's just an example of how stuff like that should be investigated. rday