Re: Will be my R9 M375 supported on any current linux distro?
Another User was also inquiring about a Linux Driver for the Radeon 530 which AMD doesn't support any more with updates in Linux. Seems like you are in the same boat with newer drivers.
On that thread I found a updated Linux Driver that may support your GPU card with a newer AMD Driver. But it is an "Unofficial" PPA Linux package. So you would need to research it and see if you want to take a risk and install it and see if it updates your GPU card driver. Here is the website: Updated Open Graphics Drivers - since 2011! : Oibaf