Few drivers use ccflags-* in their top directory to enable -DDEBUG, but don't have config options to enable debug in the sub-directories. They should want the subdirectories inherit the debug flag from the top.
Use subdir-ccflags-* instead of ccflags-* to inherit the debug settings from Kconfig when traversing subdirectories.
We primarily find this issue when debugging PCIe and other drivers may also have this issues. Previous discussion can be find at https://lore.kernel.org/linux-pci/1612438215-33105-1-git-send-email-yangyico...
Junhao He (4): driver core: Use subdir-ccflags-* to inherit debug flag hwmon: Use subdir-ccflags-* to inherit debug flag pps: Use subdir-ccflags-* to inherit debug flag staging: comedi: Use subdir-ccflags-* to inherit debug flag
drivers/base/Makefile | 2 +- drivers/base/power/Makefile | 2 -- drivers/hwmon/Makefile | 2 +- drivers/pps/Makefile | 2 +- drivers/staging/comedi/Makefile | 2 +- drivers/staging/comedi/drivers/Makefile | 1 - drivers/staging/comedi/drivers/tests/Makefile | 2 -- drivers/staging/comedi/kcomedilib/Makefile | 2 -- 8 files changed, 4 insertions(+), 11 deletions(-)