Found after building next-20230620 ARC with axs103_defconfig:
drivers/base/regmap/regcache-maple.c:113:36: warning: 'lower_last' is used uninitialized [-Wuninitialized]
drivers/base/regmap/regcache-maple.c:113:23: warning: 'lower_index' is used uninitialized [-Wuninitialized]
drivers/base/regmap/regcache-maple.c:114:36: warning: 'upper_last' is used uninitialized [-Wuninitialized]
drivers/base/regmap/regcache-maple.c:114:23: warning: 'upper_index' is used uninitialized [-Wuninitialized]
Found after building next-20230620 ARC with axs103_defconfig: