first this one on 4.7
arch/arm/mm/dma-mapping.c: In function '__dma_alloc':
arch/arm/mm/dma-mapping.c:238:25: warning: array subscript is above array bounds [-Warray-bounds]
error, forbidden warning: dma-mapping.c:238
make[1]: *** [arch/arm/mm/dma-mapping.o] Error 1
make: *** [arch/arm/mm] Error 2

then on 4.4.3 this
arch/arm/mm/dma-mapping.c: In function '__dma_alloc':
arch/arm/mm/dma-mapping.c:238:25: warning: array subscript is above array bounds [-Warray-bounds]
error, forbidden warning: dma-mapping.c:238
make[1]: *** [arch/arm/mm/dma-mapping.o] Error 1
make: *** [arch/arm/mm] Error 2