Re: [PATCH RFC v2 4/4] PCI: hotplug: Add quirk For Dell nvme pcie switches

[Alex_Gagniuc]

On 2/21/19 8:05 PM, Oliver wrote:
> On Fri, Feb 22, 2019 at 5:38 AM <Alex_Gagniuc@xxxxxxxxxxxx> wrote:
>> On 2/21/19 1:57 AM, Lukas Wunner wrote:
[snip]
>>> If the quirk is x86-specific, please enclose it in "#ifdef CONFIG_X86"
>>> to reduce kernel footprint on other arches.
>>
>> That's a tricky one. If you look at p. 185 of [1], items 9, 11, and 12
>> are standard x16 cards that would fit in any x16 slot. Those cards have
>> the offending switches.
>>
>> On the one hand, you could take the cards and backplane and put them in
>> a non-hax86 system. On the other hand, I don't see why someone would
>> want to do this.
> 
> I have a couple of POWER boxes with Dell branded switch cards in them.
> I have no idea why either, but it does happen.

The hardware debouncer, I think, is on the backplane, so you'd really 
need both the switch and backplane combo. I've seen other marketing 
departments call the switches "NVMe HBA".

Alex