my battery drain was increased, also the mobile shutting down when I used the camera even if battery more than 30%.
i thought all of those problems cuz of update not the battery, when I searched many times I found many guys written the same problems!
i contacted Huawei customer services, they told me that Huawei removed all software from their sites cuz of wrong use from some customers
here are how to Rollback your device without any problems.
1) First, download Android Nougat Rollback Package for Huawei P9 from here
middle east http://download-c.huawei.com/downloa...&siteCode=kwen
2) Now create a folder dload in the root of your SD card and place the update.app file in that folder.
3)Now turn off your device.
4) Now press “Volume Up + Volume Down and Power Button” together. The update process will start automatically.
5) Now wait for some time to complete the process. Your firmware version should now be on “B300”.
6) Now download the full Marshmallow firmware from here
middle east http://huawei-firmware.com/rom/huawei-p9/eva-l19/324
or you can choose your eligible software from here
7) Now move the update.app file in SD card folder (Replace the rollback update.app file).
8) Now again press “Volume Up + Volume Down and Power Button” together to Downgrade Huawei P9 from Android Nougat to Android Marshmallow
This is the complete guide to Downgrade Huawei P9 from Android Nougat to Marshmallow. If you have any questions comment below.