FAQ and Help

TROUBLESHOOTING GUIDE :

  • REMEMBER: As there are currently 17x supported variants, only one of which I own, so it’s not always possible to reproduce your “issue”.
  • Please provide as much information as possible.
  • Without resetting your device to a stable unmodified baseline, any potential troubleshooting or logs could be meaningless. I don’t wish to debug the ROM, just the kernel !
  • So please follow the guidelines set out below. Users can’t “read minds”.
  • Without providing important information below, we are unable to help with YOUR “issue”There are way too many variables, so at least try to narrow down any trends !
  1. Search THIS SITE, and Google until your eyes bleed before posting
  2. Provide as much information as possible.

    – Device model
    – Firmware version
    – ROM name / version
    – Kernel version
    – Modem version
    – Bootloader version
    – Synapse settings (try default)
    – Installed tweaks and apps etc (Xposed ?)
    The exact steps you’ve taken to try resolve the issue yourself.

  3. Exact steps to reproduce the issue. Provide screenshots if able.
  4. Does it work with older / other versions etc
  5. Reset your device to a stable baseline (ie. FULL WIPE: system, cache, dalvik-ART + Odin STOCK ) + only custom TWRP recovery and SkyHigh Kernel 
  6. Possible logs

 

FAQ & HELP :

CAN I BUILD A KERNEL FOR YOUR __XX DEVICE ?

  • Sorry. I don’t have the spare time for any more variant support.

 

UX ROM : ALWAYS on DISPLAY (AoD)

  • Just for “proof of concept”, I have actually ported the code from N920K kernel source, but unfortunately it is not fully compatible with STOCK TouchWiz firmware that SkyHigh is intended and optimized for.
  • With so many variant I unselfishly support, this would mean that I would need to double the contributions I currently make (not gonna happen). In addition, in its current state, AoD is a battery draining feature I would not use.
  • Sorry, look elsewhere until official Samsung UX firmware is released for my N920C device. I might re-consider then.

 

DO I “NEED” SYNAPSE

  • THERE IS NO “NEED” !!
  • It is “recommended”, which is OPTIONAL, and not “needed”.
  • It is for ADVANCED or adventurous users who wish more control of their device or use various features I’ve added.
  • Using any other optional tweaking or control app may conflict & many features and options won’t be available.

 

WHY WAIT 120 SECS

  • The kernel and Synapse scripts need time to boot up properly and allow SU permission.
  • There are scripts / code that have a deliberate delay and must run after Synapse. These are not user optional.
  • Synapse has a stability check on boot. You may get “synapse boot cancelled”.
  • Thermal throttling will be trying to limit many things, let the device settle

 

OTHER PARTY CAN NOT HEAR VOICE ON SPEAKER PHONE

  • It could be a conflict in the system/etc/mixer_*.xml. I don’t know for sure, but if I exclude the sound mod, then this “fixes” the problem.
  • As I cannot reproduce the issue (and the majority), then the audio mod stays.
  • Unfortunately, making it optional would require to build kernels without and create much more work for many device I don’t actually use.
  • Either live with it, or use another kernel. Sorry.

 

“NO UCI SUPPORT”

  • It’s a ROM busybox compatibility issue !!
  • Re-flash kernel as per Installation Instructions. (kernel install zip flashes proven busybox binary to /system/xbin)
  • Have you flashed SkyHigh on an unsupported variant? Then Synapse UCI support is unavailable. In addition to that, many kernel defaults, features and optimizations are not set for correct integration of kernel & ROM. You are all on your own !!

 

BACKUP / RESTORE ISSUES

  • It’s a ROM busybox or sqlite3 compatibility issue !!
  • Re-flash kernel as per Installation Instructions. (kernel install zip flashes proven busybox binary to /system/xbin)

 

BACKUP & RESTORE

  • DO NOT restore profiles from different kernel version
  • Refer to THIS post for “how-to” screen-shots
  • Refer to THIS post for a “how-to” video

 

LOADABLE MODULES AREN’T WORKING

  • Check your /system/lib/modules directory. Are any ____.ko present?
  • Did you flash a ROM or wipe the system partition at any point? Doing this will remove them !
  • Re-flash the kernel will install the modules.
  • If modules aren’t installed after flash, then re-flash and manually mount system in recovery first.
  • You can check running modules in terminal with:

lsmod

 

KTOONSERVATIVE GOVERNOR

  •  Some info from the author HERE

 

DT2W & COLOR CONTROL

  •  No, I cannot make it work properly with single source for all supported variants

 

CPU POWER CONSUMPTION

 

STUCK ON SAMSUNG BOOT LOGO AFTER FLASH

  • Ensure you flashed the correct kernel for your device model and firmware
  • Ensure your download is not corrupted. Check MD5 hash or re-download
  • Your current base firmware (ROM, boot-loader version etc.) may be incompatible – UPDATE from Sammobile.com to latest with Odin and try again.

 

BATTERY TIPS (requires updating !! )

  • Try some (or combination) of the CPU MULTICORE features in Synapse:

HMP profile = Default (values are battery orientated)

Power Aware Scheduling (slight performance cost) = Enabled

HMP LITTLE Packing (slight performance cost) = Enabled

PEWQ (power-efficient workqueue) (slight performance cost) = Enabled

  • Set A57 & A53 Interactive governor profile = Battery
  • Set Input-Booster for key/touchkey profile = Battery
  • Multi-tasking: enable UKSM & “low” or “quiet” profile (slight performance/battery cost)

 

PERFORMANCE TIPS (requires updating !! )

  • Set A57 & A53 Interactive governor profile = Performance
  • Set A57 & A53 Interactive governor = Turbo Mode (battery cost)
  • Set HMP threshold profiles = Stock or Performance
  • Once in a while:

Optimize Databases

FSTrim

 

RANDOM REBOOT

  • Don’t UV or UC CPU or GPU
  • Use SkyHigh defaults
  • Use a stock UNMODIFIED ROM for your device variant
  • No tweaks, Xposed or other CPU control apps installed
  • Follow the TROUBLESHOOTING GUIDE

 

ASV_GROUP (ALL DEVICES ARE NOT CREATED EQUAL)

  • THIS is an example from my Exynos5420 source. Similar idea for Exynos4

 

CAN I INCLUDE SkyHigh KERNEL IN MY ROM

  •  Although I do appreciate your contribution, if you could please do not include my kernel in any ROM package etc. This policy goes for anyone.
  • Having my kernel distributed outside my development blog just removes a lot of credit and more importantly, constructive user feedback that could be helpful to my development or user issue.

 

DOWNLOAD LINK NOT WORKING

  •  I want to keep this project all in one place – ☆☆ NO MIRRORS ☆☆
  • Please try again in a few minutes

 

POOR CPU/GPU BENCHMARK or GRAPHICS PERFORMANCE

  •  Disable any CPU MULTICORE options in Synapse
  • Disable any Battery profiles in Synapse. Set to default or Performance.
  • Allow the device to cool. Repetitive testing will heat the device hardware and invoke thermal throttling and lead to decreased benchmark.
  • HIGH CPU/GPU OC == excessive heat == thermal throttling == reduced clock frequency == DECREASE PERFORMANCE

 

DYNAMIC MANAGEMENT OF DIRTY PAGE WRITEBACKS

by Christopher83

  •  This feature allows to have two different intervals for dirty page writebacks and to dynamically manage them when the system has been resumed (it’s active) or when has been suspended.
  •  Three new procfs parameters are exposed inside /proc/sys/vm path:

1. dynamic_dirty_writeback is the activation status of this feature, set 1 to enable it, set 0 to disable it and use the standard behaviour

2. dirty_writeback_active_centisecs is the interval for the dirty page writebacks when the system is active (screen on)

3. dirty_writeback_suspend_centisecs is the interval for the dirty page writebacks when the system is suspended (screen off)

 

TCP/IP NETWORK SECURITY

Thanks to zeppelinrox & V6SuperCharger

  • Hardening the TCP/IP stack to SYN attack
  • Bump up tw_buckets in case we get DoS’d
  • Ignore pings
  • Don’t cache connection metrics from previous connection
  • Don’t pass traffic between networks or act as a router
  • Enable spoofing protection (turn on reverse packet filtering)
  • Don’t accept source routing
  • Don’t accept redirects
  • Further reading:

http://www.cyberciti.biz/faq/linux-kernel-etcsysctl-conf-security-hardening

http://www.symantec.com/connect/articles/hardening-tcpip-stack-syn-attacks

 

CHROMECAST – STREAMING PROBLEMS

  •  Lock screen MUST be enabled (simple screen lock swipe) I don’t know why but it breaks the chromecast app’s ability to resume smoothly if switched off
  • Synapse > Network > DTIM (both screen ON & OFF) = 1
  • Synapse > Network > WIFI Power Mode (screen OFF) = FAST
Advertisements