Auto complete php functions doesn't work for me at all

Please provide more details about your actions, expectations and actual behavior.

in any php file, with ctrl+space ı see "no suggestion" message

You have to actually type a few letters, then hit ctrl+space to get the code completion. Also, your files need to be in the same project.
If you want to get a better and more precise answer, try to tell us step by step what exactly you are doing and what you expect to get when you are doing it.

Please doublecheck your own advices before trying to help somebody. Ctrl-Space can be invoked without ANY text prefix.

Please include full name of IDE distribution file you installed.

True, but i though he isn't getting the code completion for his functions, not that he isn't getting it at all. Unfortunately, the lack of details in his post won't get him a clear answer.

You ignoring my requests and keeping to repeat same thing
Please re-read the thread and post required information.
We are unable to help you otherwise.