> One drawback of your approach is that > you cannot set KBUILD_CFLAGS_W1_20200930 > until you eliminate all the warnings in the > sub-directory in interest. > (i.e. all or nothing approach) Hi Mashiro That actual works well for my use case. drivers/net/ethernet is W=1 clean. So is drivers/net/phy, drivers/net/mdio. Developers generally clean up a subsystem by adding W=1 to the command line because that is the simple tool they have. And my aim here is to keep those subsystem W=1 clean. I don't care about individual warnings within W=1, because those subsystems are passed that stage already. Andrew