With Arnd's script [1] help, I found some bugfixes in Spreadtrum 4.14 product kernel, but missing in v4.14.141:
86fda90ab588 net: sctp: fix warning "NULL check before some freeing functions is not needed" 25a09ce79639 ppp: mppe: Revert "ppp: mppe: Add softdep to arc4" d9b308b1f8a1 drm/i915/fbdev: Actually configure untiled displays 47d3d7fdb10a ip6: fix skb leak in ip6frag_expire_frag_queue() 5b9cea15a3de serial: sprd: Modify the baud rate calculation formula 513e1073d52e locking/lockdep: Add debug_locks check in __lock_downgrade() 957063c92473 pinctrl: sprd: Use define directive for sprd_pinconf_params values 87a2b65fc855 power: supply: sysfs: ratelimit property read error message
[1] https://lore.kernel.org/lkml/20190322154425.3852517-19-arnd@arndb.de/T/
Chris Wilson (1): drm/i915/fbdev: Actually configure untiled displays
David Lechner (1): power: supply: sysfs: ratelimit property read error message
Eric Biggers (1): ppp: mppe: Revert "ppp: mppe: Add softdep to arc4"
Eric Dumazet (1): ip6: fix skb leak in ip6frag_expire_frag_queue()
Hariprasad Kelam (1): net: sctp: fix warning "NULL check before some freeing functions is not needed"
Lanqing Liu (1): serial: sprd: Modify the baud rate calculation formula
Nathan Chancellor (1): pinctrl: sprd: Use define directive for sprd_pinconf_params values
Waiman Long (1): locking/lockdep: Add debug_locks check in __lock_downgrade()
drivers/gpu/drm/i915/intel_fbdev.c | 12 +++++++----- drivers/net/ppp/ppp_mppe.c | 1 - drivers/pinctrl/sprd/pinctrl-sprd.c | 6 ++---- drivers/power/supply/power_supply_sysfs.c | 3 ++- drivers/tty/serial/sprd_serial.c | 2 +- include/net/ipv6_frag.h | 1 - kernel/locking/lockdep.c | 3 +++ net/sctp/sm_make_chunk.c | 12 ++++-------- 8 files changed, 19 insertions(+), 21 deletions(-)