Okay, today I have learnt a lot again.
First I ditched the kernel and reloaded a fresh from github. Then I tried to apply the patches manually. Well, it was a bad idea. The kernel compilation failed. Few hours pointless fighting, I decided to start over again.
Delete kernel, refresh from repo then apply the patches. I managed to download all patches as yxz.patch file, then I was able to install them on the kernel.
Plus I pushed this all changes into my repo. (The links of the two commits can be found on the previous post.)

Then I recompiled the kernel and based on @mautz instruction I created a flashable zip. It is available here edp17kernel-cm-12.1

!!!! I have not yet tested this!!!! But in theory if we flash this kernel over the last wip0.15 image, bluetooth and other stuff should work.
Tomorrow I will test and if it works I will build a new image with this kernel.

I have tested the gps in wip0.15 with @mautz kernel and it works!

Now, I am half dead tired so good night everyone.

Regarding tge compile error in hidp/core this will fix it: https://github.com/mautz-kernel/andr...7c12f1e585cbba

When re-downloaded the whole kernel again and applied all the recommended patches (from your earlier post) with the 'git apply', I didn't get the compilation error. I just checked and this code, you mentioned in this post, is still in the source.
Do I need to keep it or remove it?

On the other hand I flashed this kernel on the wip0.15 and deleted the 'lib/systemd/system/droid-hcismd-up.service' and the 'bluetooth.service.wants' folder because they were related to the hadk's bluetooth solution, but the bluetooth still not work.

Maybe there is something else in the kernel config to switch on or off? And/or another patch to apply?
Thank you.

I will wait for a more stable version before updating, but of you need to test something specific let me know and I'll flash your image!

Yeah, don't worry about it for a while.
It seems I need to fix the bluetooth and the video recording/playback.
(Although these are missing I am already using it as daily driver. )

I have built a new image (wip0.16) where I put the edp17 kernel into. (So, no need to flash over on the installation.)
Now the only (how I know) outstanding issues are the bluetooth and video recording.
(The time and date change still requires to re-install the timed-qt5 package, and the Storeman still need to do a pkcon update.)
I have ran the 3DMark-Ice Storm Extreme to test the 3d acceleration. I got 9155 points whatever it means.

Anybody has an idea for fixing the bluetooth and video recording, please share. Thank you.

Sorry can not test the new version before the end of the week.

No problem, don't worry. Thanks.
I am not creating new image until find solution for the bluetooth and video recording issues.
(However I probably will play with the kernel to see whether I can find any improvements.)

Good news!
I have found the reason why the bluetooth didn't work.

Now it can be switch on/off and be paired with other devices.

All we need to do is install the 'connman-tools'
I have tested with:
- Galaxy S7 - paired correctly
- Bonai bluetooth headset - audio is routed correctly to the headset
- Rii Mini 518 Pocket Size Mini Wireless Bluetooth Keyboard - it works with Sailfish flawlessly

Screenshot:


Now, the only outstanding issue is the video recording/playback.

What is the problem with video playback?