Linux 4.2 Release - Main Changes, ARM and MIPS Architectures

Linus Torvalds released Linux Kernel 4.2 last Sunday:

So judging by how little happened this week, it wouldn’t have been a mistake to release 4.2 last week after all, but hey, there’s certainly a few fixes here, and it’s not like delaying 4.2 for a week should have caused any problems either.

So here it is, and the merge window for 4.3 is now open. I already have a few pending early pull requests, but as usual I’ll start processing them tomorrow and give the release some time to actually sit.

The shortlog from rc8 is tiny, and appended. The patch is pretty tiny too.

Go get it,

Linus

Some notable changes made to Linux 4.2 include:

File systems
- New features for F2FS including per file encryption
- CIFS support SMB 3.1.1 (experimental)
Cryptography – Jitter Entropy Random Number Generator, Chacha20 stream cipher and Poly1305 authentication (RFC7539),New RSA implementation. See lwn.net for details.
AMD GPU driver added support for AMD “Tonga,” “Iceland,” and “Carrizo” systems. That driver has now over 400,000 lines of code…
Networking
- “Flower” packet classifier allows to “classify packets based on a configurable combination of packet keys and masks.”
- Driver for GENEVE (Generic Network Virtualization Encapsulation) tunnel

Some of the new features and improvements specific to the ARM architecture include (With a focus on Allwinner/Rockchip/Amlogic/Mediatek processors often discussed in this blog):

Allwinner:
- A10/A10s/A13/A20/A31/A23 – SRAM Controller
- A23 – SMP support, architected timer support
- A31/A31s – CPUFreq support
- A33 – Machine support, Bring-up sharing most drivers with A23, pinctl driver, PIO controller
- A80 – Architected timer support, USB support
- AXP221 PMIC driver
- New boards and devices: LinkSprite pcDuino3 Nano, Cubietech Cubieboard4, Gemei G9, Auxtek T004, Utoo P66, Wexler TAB 7200, MK808C, Jesurun Q5, Xunlong Orange Pi, Xunlong Orange Pi Mini, Sinlinx SinA33

Rockchip
- Fixes for GPU DRM driver
- RK3368 – Added pinctrl and Ethernet (dwmac) support
- Device tree – Files relicensed under GPLv2/X11 dual-license, Enable A12 HW PMU events in RK3288 boards, and TSADC for Firefly and PopMetal boards
- Fixed IR receiver bug and modify some GPIO code in RK3288
Amlogic – Added documentation to the clock controller… nothing else.
Mediatek
- Fixed clock registration in MT8135
- Small changes and fixes to pinctrl driver
- Added driver for Mediatek MT8173 I2C controller
- Some fixes for PMIC
- MT7601U driver (WiFi device)
- Pinctrl driver for MT8127, MT6397,
Qualcomm
- Added SPMI PMIC Arbiter device tree node for MSM8916
- Added 8×16 chipset SPMI PMIC’s nodes
- Added MSM8916 restart device node
- Added initial set of PMIC and SoC pins for APQ8016 SBC board
Samsung
- Fix exynos3250 MIPI DSI display and MIPI CSIS-2 camera sensor
- Bring back cpufreq for exynos4210
ARM64
- New processors: Hisilicon ARM64 SoCs (e.g. Hi6220)
- Various fixes for ARM64 for ACPI, MMU, SMP, perf, and more.
- Enabled EDAC on ARM64
- Support for Hikey board, ARM Juno r1 board
Various changes to some Atmel and Marvell processors, see Free Electrons blog post for details.
Other new ARM SoCs & hardware platforms – Freescale i.MX 7Dual, ZTE ZX29670, Buffalo WXR-1900DHP, ASUS RT-AC87U, SmartRG SR400ac, Compulab CM-A510, and more

There has also been some interesting changes for the MIPS architecture:

many bug fixes: LLVM build issue, KVM fixes, fix seccomp MIPS64, fix for oprofile (get_c0_perfcount_int), Fix JR emulation for R6, etc…
Some code cleanups (fixed misspellings, removes some code)
Added support for appended DTP
Improvements for R12000, R3000, Broadcom BCM47xx and BCM63xx, ATH79
Large patchset for Ingenic JZ4740 SoC
Added support to Pistachio SoC
New MIPS platforms: MIPS Creator CI20 board and XWR-1750 board

A complete changelog for Linux 4.2 should soon be published on Kernelnewbies.org, and you’ll probably also want to look at their ARM architecture and drivers sections for more details about to various platforms including ARM and MIPS. I’ve also generated a complete Linux 4.2 Changelog with comments only (13.9MB) using git (git log v4.1..v4.2 --stat)

Jean-Luc Aufranc (CNXSoft)

Jean-Luc started CNX Software in 2010 as a part-time endeavor, before quitting his job as a software engineering manager, and starting to write daily news, and reviews full time later in 2011.