[PATCH 1/1] nvme: check for Identify CNS 06h opcode support

[Aviv Heller]

Thanks for your feedback.

> There's no requirement that a controller report a particular version in order
> to implement a TP, though. It's perfectly valid for a controller that reports
> version 1.4 may implement this feature. We just don't have a way to konw if
> a controller implements this CNS (TPAR 4135 aims to fix that), so we just try it
> and look for success.

That's good to know. I didn't notice that this CNS is defined in a TP.

> The driver doesn't care if the controller doesn't support this identification. If
> the controller doesn't support it, we should get an Invalid Field status. The
> driver will carry on as before, so it should be harmless. What problem is this
> actually fixing?

It was noticed when we got an invalid CNS error print from our NVMeoF target.
We then thought that if support could be tested, avoiding issuing the command
is the right way to go.

This is not the case, though.