[Galaxy Tab S2 Q&A, Help & Troubleshooting] retiredtab:
The S2 wifi blobs have now been incorporated into the Aug 25 17.1 builds.

Please take 10 minutes to read all of post #1 and #2. lpedia and I have spent 5 days troubleshooting this together and want to present our wifi findings. DO NOT USE this thread to report any other problems, it's only for exynos5433 S2 tablet wifi. If this is unreasonable, then stop reading. Thank you.

If your device's wifi is not connecting after a restart and/or wake from sleep, and/or dropping out at random, this could be because the 17.1 code is using Samsung Galaxy S6 wifi blobs instead of its stock S2 wifi blobs. This commit was made in 17.1 at

gts2: Import Galaxy S6 BCM4358 firmware · universal5433/proprietary_vendor_samsung@f861cbf

@lpedia has confirmed that LineageOS 17.1 on his T710 has the wifi problems when using S6 blobs, but not after the S6 blobs have been replaced with stock S2 blobs. This appears to fix both non-connection at boot and not reconnecting on wake from sleep. Random dropouts are less common and were not seen during the limited testing, so it's not certain that they're gone.

FAQ

Q1. Will changing from S6 wifi blobs solve all my wifi no reconnect or disconnect problems?

A1. This has only been tested on the T710, and there's no guarantee it will help the other devices. If you want to try, follow the instructions below. Before you try, make sure to back up all your data. The following should write the stock S2 blobs to the /system partition only, but if you make a mistake you could lose your data! Back up first.

It's an easy test to see if the stock S2 blobs will help or not. If your current rom does not connect to wifi after a restart, try our proposed solution. Before you do, reboot your current rom 5 times in a row. After each reboot, see if your wifi connects. After you install stock S2 blobs, reboot your device again 5 times in a row and see if wifi connects. This will easily tell you if the S2 stock blobs have solved this one particular problem or not.

As for wifi not connecting after long/deep sleep, you should notice over 2 or 3 days if wifi connects or not after deep sleep.

Q2. Will this work on SM-T710, SM-T810, etc?

A2. Same answer as A1. It should work on any S2 tablet exynos5433 device that uses the S6 wifi blobs that are the default in 17.1 or Android 10. These instructions are only for exynos5433 devices.

As the thread grows bigger, you can see who is responding back with either positive or negative feedback and what model they have.

Q3. Will this work on RR, Havoc or LineageOS (Android 10 or 17.1)?

A3. The instructions below replace the S6 blobs with the original stock S2 blobs. The instructions provided should work regardless if it's Havoc, RR or LineageOS. All these variant OSes share the same repo (i.e. code and blobs) on github.

Q4. Is this post relevant to Android 9 or LineageOS 16.0?

A4. NO. The github repos show that Android 9 or LineageOS 16.0 used the stock S2 wifi blobs. This was changed to S6 wifi blobs in Android 10 or LineageOS 17.1. I don't know why it was changed to S6 blobs as I'm not involved with that change.

Q5. Why do I need my model and code name?

A5. In order to follow the instructions below, you need to know your model number and it's code name. The model number or device name is settings, about tablet.

You can find the code name at (scroll almost all the way down to the bottom)

Samsung

This is the Team Win website and the official home of TWRP! Here you will find the list of officially supported devices and instructions for installing TWRP on those devices.

twrp.me

For example, SM-T710 is gts28wifi.

Q6. Does it matter if my wifi is 2.4Ghz or 5Ghz or a mix of both?

A6. When reporting back to us, please state whether your network is 2.4Ghz only, 5Ghz only, or a mix of 2.4Ghz and 5Ghz. In addition, if its a mix, please let us know if it's one wifi network (same ssid) or two separate wifi networks. That is, 2.4Ghz is one ssid and 5Ghz is another ssid.

Q7. If this works, how will this be fixed for the next release of code and the future?

A7. If enough people say it fixes their wifi problems, I can submit a git pull request to Anan to revert the S6 wifi blobs back to S2 wifi blobs.

Instructions

1. Make sure adb debugging is enabled in developer options. To enable developer options, tap settings, about tablet, build number 7 times until it says developer options unlocked. Go back to settings, system, advanced, developer options, enable android debugging and rooted debugging.

Note if you are running Magisk, see posts regarding Magisk if you cannot see rooted debugging.

2. You will need git. There are instructions and download links for installing git on Windows, MacOS, and Linux at Git Guides - install git | GitHub.

3. After you install git, follow the instructions exactly below.

# make temporary vendor directory
mkdir temp
# cd to that directory
cd temp
# git the 16.0 stock drivers
git clone https://github.com/universal5433/proprietary_vendor_samsung -b lineage-16.0
# change directory to proprietary_vendor_samsung/<your device>/proprietary/system/vendor/etc
# or if Windows, to proprietary_vendor_samsung\<your device>\proprietary\system\vendor\etc
# where "<your device>" is your device's code, for example gts28wifi for the T710:
cd proprietary_vendor_samsung/gts28wifi/proprietary/system/vendor/etc
# start adb root
adb root
# remount /system as rw (it's read only by default)
adb remount
# start adb shell
adb shell
# delete S6 blobs from wifi directory
cd /system/vendor/etc/wifi
rm bcm*
rm nvr*
# There should be only .conf files left now
ls -al
exit
# you should be back at your desktop terminal prompt now
# now push all stock drivers to /system/vendor/etc/wifi
adb push wifi /system/vendor/etc
# check to make sure it got pushed okay
adb shell ls -al /system/vendor/etc/wifi
# now reboot Android
adb reboot

If the above does not work for you, or if it causes other problems, just reflash the last rom. That will overwrite the /system partition and everything will be restored.

If you do try this, please report back to this thread about whatever happened and include your device and what wifi network you are running.