Hi- This commit from v4.4.241 breaks the v4.4.y build for powerpc: 217f139551c0 powerpc/powernv/dump: Fix race while processing OPAL dump Like this: .../arch/powerpc/platforms/powernv/opal-dump.c:409:7: error: void value not ignored as it ought to be dump = create_dump_obj(dump_id, dump_size, dump_type); ^ The commit descriptions says: "... the return value of create_dump_obj() function isn't being used today ..." But that's only true for kernels >= v4.19, because they carry this commit: b29336c0e178 powerpc/powernv/opal-dump : Use IRQ_HANDLED instead of numbers in interrupt handler In v4.4 process_dump(), the only caller of create_dump_obj(), still tries to use the return value (see the error above). Applying "b29336c0e178 powerpc/powernv/opal-dump : Use IRQ_HANDLED ..." to v4.4.y fixes the problem. -Kamal