There are two reasons for build failure on arm64, arm, x86_64 and i386.

For arm64 we have identified missing patch, Patch "efd00c7 arm64: Add MIDR encoding for HiSilicon Taishan CPUs" needs to be bacported as well,

for arm, x86_64 and i386 build error log, ------------------------------------

net/ipv6/addrconf.c: In function 'addrconf_init': net/ipv6/addrconf.c:6747:22: error: 'blackhole_netdev' undeclared (first use in this function); did you mean 'alloc_netdev'? bdev = ipv6_add_dev(blackhole_netdev); ^~~~~~~~~~~~~~~~ alloc_netdev net/ipv6/addrconf.c:6747:22: note: each undeclared identifier is reported only once for each function it appears in net/ipv6/addrconf.c: In function 'addrconf_cleanup': net/ipv6/addrconf.c:6839:18: error: 'blackhole_netdev' undeclared (first use in this function); did you mean 'alloc_netdev'? addrconf_ifdown(blackhole_netdev, 2); ^~~~~~~~~~~~~~~~ alloc_netdev

For arm64 build error log, --------------------------------------- arch/arm64/kernel/cpufeature.c: In function 'unmap_kernel_at_el0': arch/arm64/kernel/cpufeature.c:909:21: error: 'MIDR_HISI_TSV110' undeclared (first use in this function); did you mean 'GICR_ISACTIVER0'? MIDR_ALL_VERSIONS(MIDR_HISI_TSV110), ^ arch/arm64/include/asm/cputype.h:141:12: note: in definition of macro 'MIDR_RANGE' .model = m, \ ^

Meta data: ------------------------------------------------------------------------ kernel: 4.19.82-rc1 git repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git git branch: linux-4.19.y git commit: 7d816e1d91b01911392b7f8f93a4a153b9af60d3 git describe: v4.19.81-145-g7d816e1d91b0 Test details: https://qa-reports.linaro.org/lkft/linux-stable-rc-4.19-oe-sanity/build/v4.1...

- Naresh