Re: [PATCH v12 0/6] Address error and recovery for AER and DPC

[Bjorn Helgaas <helgaas@kernel.org>]

On Mon, Mar 12, 2018 at 05:26:26PM -0600, Keith Busch wrote:
> On Mon, Mar 12, 2018 at 02:47:30PM -0500, Bjorn Helgaas wrote:
> > On Mon, Mar 12, 2018 at 08:25:51AM -0600, Keith Busch wrote:

> > > Per spec, DPC is the recommended way for handling surprise removal
> > > events and even recommends DPC capable slots *not* set 'Surprise'
> > > in Slot Capabilities so that removals are always handled by DPC. This
> > > service driver was developed with that use in mind.
> > 
> > Thanks for this tip.  The only thing I've found so far is the mention
> > of Surprise Down triggering DPC in the last paragraph of sec 6.7.5.
> > Are there other references I should look at?  I haven't found the
> > recommendation about not setting 'Surprise' in Slot Capabilities yet.
> 
> No problem, it's in the "IMPLEMENTATION NOTE" at the end of 6.2.10.4,
> "Avoid Disabled Link and Hot-Plug Surprise Use with DPC".
> 
> Outside the spec, Microsemi as one of the PCI-SIG contributors and early
> adopters of the capability published a white paper "Hot and Surprise
> Plug Recommendations for Enterprise PCIe" providing guidance for OS
> drivers using DPC. We originally developed to that guidance. The paper
> unfortunately appears to be pay-walled now. :(

Any chance you have a URL or contact info for this pay-walled white
paper?  Sounds like it might have useful information in it.