(In reply to Benjamin Bellec from comment #68)
> If I have to read the VBIOS and add I quirk in the kernel, why the kernel
> can't do this by himself ?
> 
> Moreover, I saw the previous quirk in the kernel, the max memory clock is
> often set to "120000". I guess it stands for 1.2GHz QDR which is equivalent
> to 4.8GHz. My card, like all the R7 370 are supposed to work at 5.6GHz so
> this is a serious lost of performance.
> 
> At the moment I will just return my card.

For the record:

This stuff *can't* be read from the VBIOS and has to be found by trial and
error.
You also don't have to google the steps, they are described in comment #48.

But otherwise you are right, It will limit your card and replacing it with
another one seems like the only option you have right now. At least that's what
I did too, because I don't see this bug fixed in the near future.