On 11/29/2018 11:36 AM, Bjorn Helgaas wrote: > On Wed, Nov 28, 2018 at 06:08:24PM -0600, Alexandru Gagniuc wrote: >> A warning is generated when a PCIe device is probed with a degraded >> link, but there was no similar mechanism to warn when the link becomes >> degraded after probing. The Link Bandwidth Notification provides this >> mechanism. >> >> Use the link bandwidth notification interrupt to detect bandwidth >> changes, and rescan the bandwidth, looking for the weakest point. This >> is the same logic used in probe(). > > I like the concept of this. What I don't like is the fact that it's > tied to pciehp, since I don't think the concept of Link Bandwidth > Notification is related to hotplug. So I think we'll only notice this > for ports that support hotplug. Maybe it's worth doing it this way > anyway, even if it could be generalized in the future? That makes sense. At first, I thought that BW notification was tied to hotplug, but our PCIe spec writer disagreed with that assertion. I'm just not sure where to handle the interrupt otherwise. Alex
