[PATCH] nvme: prepare support for Apple NVMe controller

[Keith Busch]

On Thu, Oct 29, 2015 at 08:46:38PM +0100, Stephan Günther wrote:
> On 2015/October/29 09:10, Jon Derrick wrote:
> > Christoph recently added a quirks mechanism where I think it would fit
> 
> To be honest we don't know what mechanism you are referring to. Please 
> give us pointer.

It's new, not merged in an official tree. A copy is on the mailing list
somewhere. I committed it to my personal tree here:

http://git.infradead.org/users/kbusch/linux-nvme.git/commitdiff/e43f1dc5d9f31380090cc6b67fd3fa43a15089e6
 
> I assume that we concur that this workaround--as well as making the nvme 
> driver claim the Apple controller--should be a runtime-decisions based 
> on the device id. That avoids both penalties in terms of cpu cycles and 
> the tedious manual binding.

Just append the Vendor + Device to struct pci_device_id nvme_id_table
if the 64 bit register access really is the only problem preventing it
from working in an NVMe compliant way. You can check at run time for
the lo_hi_[read/write]q quirk.

If it really works with only this one change to the nvme driver, I also
wonder Apple typo'ed their class code.