[PATCH 3/4] libertas: check for old, unsupported hardware

[Holger Schurig]

I got this piece of code from the 5.0.16 GPL driver, but 
implemented it differently. I mainly put it in to find out if 
YOU have such an old silicon. When people yell "my card isn't 
supported, I get this kernel error" we can still add the 
necessary support.

I don't want to add the support right now because I don't have 
this old hardware and don't know anyone with it. So no-one could 
test this.


The 5.0.16 source mentions two things needed for this old 
hardware:

* doing read-modify-write instead of just setting bits, this
  applies to IF_CS_HOST_STATUS and IF_CS_HOST_INT_CAUSE
* and an interrupt workaround

The interrupt workaround isn't in the 5.0.16 source.