[Galaxy Note 4 Android Development (Exynos)] ananjaser1211:
Apologies for the late replies, ive been very busy and haven't been able to find time to check how everything is going.

This is a common problem faced on some calls, the best solution we found was to just lower the earpiece volume a bit, and it usually is enough, the mitigation we had was to lower the incall Microphone volume to avoid echo but that has its own drawbacks, the issue itself originates because we dont have samsung's Noise cancelation / echo cancelation libraries working properly on anything beyond android 7, until we can actually fix Noise cancalation (its called NXP) we can only resort to lowering earpiece or mic

By new firmware do you mean the latest update (i.e after upgrading from a previous version of lineageOS) or as in Stock > Lineage. i have read some stuff about the whole new storage API but i cant say i have a full grasp over it, we are using latest sdfat driver but perhaps there are newer patches designed for Storage API, i am not sure but i will try to look into it when i can

Thank you! i will add it to the wiki soon and check other regions if they got updates too.

If possible could you mirror these files to another host, such as google drive, AFH etc, as i cant seem to open upload.ee, if i am not mistaken (since i had to fix the robotic issue in stock MM rom aswell), the fix was replacing the audio hal (on stock its called tinyalsa) and the audio mixer (tinyucm.conf) which activates the proper pre/post processing filters required to adjust the audio of this particular variant, sadly we cant just replace the audio HAL on lineage with a stock one (otherwise we would have done that for all variants and got rid of various audio problems)

I Should mention that this robotic audio problem ONLY happens on the korean variants with the samsung modem, the same modem used by the galaxy S6/S7 etc and they have no problems with audio using the lineage AOSP hal (the same one we use), so i do believe the problem could be due to bad audio config (since we need to translate the stock config file into a newer format used by newer hals), i could try to experiment a bit with it but i would need S/L/K Testers again, if you are free to do that, send me a PM on @anan1211 on telegram, or XDA Private msgs if thats more conveneint, once i get the chance to work on the note again ill send some test files.

The other cause could be something in the tinyucm audio HAL itself, if thats the case then i think it would be far too difficult to reverse engineer what it does in calls to eliminate robotic calls.

what you can do however is to grab me a logcat on lineage while doing calls (you can use loggingkit from the first post and run the log_ball.bat file) and i can compare it to what my device produces and see if there are any weird errors

Hello, i have an N910C with XSG region (Bought in UAE), i have read and tried to debug this particular problem with another user who has the N910H model, its not unique to your device, if i am not mistaken, his device is also in the middle east, my though process was that your devices use either a newer or older wifi revision compared to my phone and its having problems with the kernel wifi driver we use (we dont use the stock Wifi driver), the ROM wifi firmware is stock, the kernel driver however is from a newer revision, perhaps its causing a conflict ? if possible, in the first page there are instructions on how to take full device logs, download the tool loggingkit, follow the instructions and run log_ball, and cycle wifi few times.

the guy also had the SAME process to fix wifi, cycling airplane mode, i did not know that it can also be done by removing the simcard though, thats a new one. he also reported the same problem on another ROM i have, Refined Nougat, so its not unique to lineage, instead its something to do with the WiFi driver we use is my best guess.

the log will help me figure out what WiFi revision your device uses, and maybe i can cross check that with my phone, and see if there is any thing i can do to fix it, i dont honestly remember why we switched to the newer wifi drivers but ill have to check, this phone is a bit weird when it comes to drivers, stock uses 2 sets of wifi firmwares, and my theory is one of them is breaking with the new driver, but thats a long shot

When it comes to BL/CP, there are no binary differences in N910C regions, aslong as it has the same bootloader / baseband revision (BL: N910CXXU2DSA2/CP: N910CXXU2DSA1) for example would be identical to other regions, what differs in say XSG vs KSA vs BTU would be in the CSC_* tar only, but that is only for mobile networks, region specific features and restrictions etc, ROMs like lineage do not contain such configurations.

When it comes to the wifi chip revision, this is at the hardware level, devices get board level revision updates (our phone if im not mistaken has 13 different board revisions), but since this works fine on stock we should be able to figure out a way to make all revisions work properly on lineage)

i will add a github issue page on this so it does not slip my mind, once you can send over the logs so i can check better.

Thank you for the report!