v5.9-rc1 commit reliably breaks pci nvme detection

[Jens Axboe]

On 8/20/20 11:12 AM, Christoph Hellwig wrote:
> On Thu, Aug 20, 2020 at 11:10:58AM -0600, Jens Axboe wrote:
>> To be fair, I've only heard this one complaint about it, so hopefully it's
>> not too widespread. I'm on an x86-64 laptop myself with nvme, and it works
>> just fine :-)
> 
> The cause for this is the weird NVMe of by ones, where 0 in a field
> means 1.  So for the overflow to happen you need a controller that
> supports USHORT_MAX queue entries.  Which don't seem to be all that
> common.

Yeah, don't think I've ever seen those. I come across 1023 and 128 all
the time, but I don't have one in my arsenal of NVMe drives that is
any different than those two.

-- 
Jens Axboe