The Linux kernel 4.4.20 LTS patch contains various architecture improvements, in particular for ARM, AArch64 (ARM64), Alpha, ARC, AVR32, Blackfin, CRIS, FR-V, Hexagon, IA64, M32R, METAg, MicroBlaze, MIPS, MN10300, Nios II, OpenRISC, PA-RISC, PowerPC (PPC), s390, SH, SPARC, and x86, as well as fixes to the EXT4, Btrfs, F2FS, FUSE, NFS, and kernfs filesystems. The networking stack received small improvements to the IPv6 and TIPC (Transparent Inter-process Communication) protocols, there are several core kernel enhancements, and it looks like the rest are updated drivers, this time for USB, TTY, GPU (mostly Intel i915)., PINCTRL, Ethernet, IRQ Chip, MMC, MD, LightNVM, InfiniBand, Clocksource, BUS, and iiO devices.