Unable to use DAHDI

I have for some time tried to add dahdi support to asterisk. my latest effort was on asterisk 15.5 on fedora 28. i started with asterisk 13 and fedora 25. in all versions i tried i have been unable to add dahdi support. Since i mostly configure only sip support with soft phones then it does not matter, but still i would like to be able to add support for a regular phone line.

In my search of internet i can see that there has been done a change in the Linux kernel that breaks the configuration of dahdi, and it seems to me that it is a well known fact. there are some patches out there that i tried with no success.

is there anyone that know what to do? is there any development on the side of the dahdi drivers?