I have 2 systems both are exactly the same hardware.
on the first box, I installed the ebuntu efixt 16.04.4 desktop, then upgraded to version 4.15.0-43-generic and run as expected. (I can see my bus i2c devices)
The second package was already installed with the Ubuntu 16.04 desktop kernel 4.4.0-71, Ubuntu dident correctly detected the i2c device bus.
So first step, I changed the startup of bios into efi boot loader.
boot the correct system but still do not see the i2c bus properly.
The second step was to upgrade to the same kernel as in the first 4.15.0-43-generic box.
After upgrading to 4.15, Ubuntu does not load many drivers, such as the i915.
Ubuntu also does not see the i2c bus at all (I guess the drivers are missing)
so why does this happen? same same core material
how to solve this?