[KERNEL] Polar Kernel R27 [25/08/2019]

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Senior Member
Jul 15, 2013
WOW! Great kernel. Nice surprise. Keep up the good work dev.
Now can't wait for next release - that's how good this kernel is!!!

Sent from my MI 8 using Tapatalk


Senior Member
Jul 15, 2013
@YumeMichi Mate, your GitHub for Q release looks exciting. Do you need testers for Q? I can be a tester.

Also, consider opening Telegram group for your amazing kernel mate. It will make it more popular and maybe your work will get more appreciated and also this is most underrated kernel ever for M8!!!

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    #include <std_disclaimer.h>
     * Your warranty is now void.
     * I am not responsible for bricked devices, dead SD cards,
     * thermonuclear war, or you getting fired because the alarm app failed. Please
     * do some research if you have any concerns about features included in this kernel
     * before flashing it! YOU are choosing to make these modifications, and if
     * you point the finger at me for messing up your device, I will laugh at you. Hard. A lot.


    Kernel features:
    • Compatible with MIUI (Except DC dimming and Game toolbox)
    • Linux 4.9.189 with CAF LA.UM.7.3.r1-08200-sdm845.0 and latest Google android-4.9 merged in
    • Compiled with GCC 9.1.0
    • CPU Input Boost & Devfreq Boost Driver
    • Simple Thermal Driver
    • Dynamic Stune Boost
    • Simple Low Memory Killer
    • SchedTune Assist & CPUSet Assist
    • Software CRC check disabled by default
    • Pixel 3 Energy Model
    • Full F2FS support, F2FS rapid GC, optimized F2FS extension list
    • Exposure Adjustment Driver, improve PWM flicker. (Working in process, automatic brightness switching is a bit stiff)
    • Build-in WireGuard VPN tunnel
    • Optimized UFS Driver
    • Worldwide power efficient workqueue
    • Vibration Adjustment
    • Sound Control
    • dts_eagle Support
    • KLaspe and KCAL Support
    • Pass SafteyNet without Magisk
    • Enable all TCP algorithms
    • Optimized procfs
    • Optimized Memory Management
    • Many other misc improvements (Check my github commits)


    Flash guide:
    IMPORTANT: Restore stock boot.img before flashing this kernel.
    • Download PolarKernel-Rxx-xxxxxxxx-dipper.zip
    • Flash PolarKernel-Rxx-xxxxxxxx-dipper.zip
    • Reboot

    Uninstall guide:
    • Download PolarKernel-Removal.zip
    • Flash PolarKernel-Removal.zip
    • Flash you kernel and reboot

    Build guide:

    F2FS support:
    • Download F2FS-dipper.zip or F2FS-dipper-foreencryption.zip
    • Reboot into TWRP
    • Format /cache and /data to F2FS
    • Reboot into TWRP again
    • Mount /vendor
    • Flash F2FS-dipper.zip or F2FS-dipper-foreencryption.zip
    • Reflash Polar Kernel to apply F2FS optimization
    • Reboot

    Contributors (The following list is not prioritized.):
    • bgcngm, LineageOS maintainer
    • nathanchance, android-linux-stable maintainer
    • kerneltoast, author of CPU Input Boost, Devfreq Boost, Simple Thermal Driver and Simple LMK
    • kdrag0n, most of the patches came from proton kernel for bluecross by kdrag0n
    • DevriesL, author of Exposure Adjustment driver
    • arter97, implement F2FS rapid GC to Android
    • YaroST12, author of SchedTune Assist, CPUSet Assist
    • 0ctobot, backport many optimizations from kerneltoast's wahoo project
    • There are many other people I can't mention one by one.

    If you like my work, please consider buying me a coffee. :)

    XDA:DevDB Information
    Polar Kernel for Mi 8, Kernel for the Xiaomi Mi 8

    Source Code: https://github.com/YumeMichi/kernel_xiaomi_sdm845

    Kernel Special Features:

    Version Information
    Status: Stable

    Created 2019-04-16
    Last Updated 2019-08-25
    R19 changelog
    • Merge Linux 4.9.181
    • Merge CAF tag LA.UM.7.3.r1-07800-sdm845.0
    • Merge Google android-4.9
    • Switch to GCC 9.1.0 compiler
    • Optimize builds for Kryo 385
    • Bring back Exposure Adjustment driver and make it configurable
    • Switch to Simple LMK
    • Update CPU Input Boost driver
    • Add SchedTune Assist
    • Add CPUSet Assist
    • Enable RCU Boost for improved responsiveness
    • Merge f2fs/linux-4.9.y, Rapid GC updates
    • Improve EAS
    • Update Crypto
    • System timer to 250Hz
    • Improve QoS latency
    • Improve PM QoS power efficiency
    • Max readahead to 64KB
    • Optimize binder/ion memory allocations
    • Optimize IOMMU Driver for improved performance
    • Reduce logspam
    • Etc. Full change log: https://github.com/YumeMichi/kernel_xiaomi_sdm845/commits/master
    R23 changelog
    • Fully rebase on latest CAF code
    • Update to Linux 4.9.186
    • Update CAF tag to LA.UM.7.3.r1-07900-sdm845.0
    • Merge latest Google android-4.9 updates
    • Combine dipper and equuleus into one flashable zip
    • Remove many garbages commits
    • Memory management big update
    • Avoid dynamic allocation of small buffers in multiple drivers
    • Treewide dynamic allocation avoidance
    • Optimize UFS driver
    • Oxtensive EAS scheduling overhaul (reduce UI latency, great performance)
    • Disable many debug logs to reduce system overhead
    • Backport zsmalloc/zswap from mainline
    • Convert several subsystems to use Hotplug State Machine
    • Fix SLMK bug
    • Remove Spectrum support (Do what you want)
    • Add Maple I/O Scheduler
    • Update Klapse and WireGuard version
    • Fix BT audio issue
    • Add dts_eagle support
    • Etc.
    R24 changelog
    • Update to Linux 4.9.188
    • Merge android-4.9 (F2FS updates)
    • Fix reboot to bootloader on latest MIUI dev
    R27 changelog
    • Update to Linux 4.9.189
    • Merge android-4.9
    • Merge
    • EAS/Scheduler updates
    • Disable many VLA usage
    • Optimize memchr,strlen,memcmp,memcmp routines
    • Build with GCC -Werror
    • Separate dipper and equuleus into diffreent flashable zip again. (This might fix touch issue)
    • Enable MTK MT7601U support
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