Hikey960 HDMI doesn't work on Debian

Recently I started to use Hikey960 and I enable to work with Debian and new version of linux kernel by following below post.

I download the requirements from

I checked I can access to the console though serial and ssh also, and wifi is activated.
However, the HDMI doesn’t work, which means nothing appears on the screen (normal Acer 24 inch) even I connected the cable in both cases of after boot and before.
I tried it with 2 different displays and cables, so probably is not a equipment problem.

Does it usually work, of it’s actually existing problem??

Its a known problem. Actually out-of-box Debian kernel doesn’t have support for HDMI.

One option is to install 96boards-hikey kernel using instructions from below post:

Thanks for your reply!
I’m gonna try the flow.