On Wed, Mar 17, 2021 at 08:09:52PM +0100, Lukas Wunner wrote: > On Wed, Mar 17, 2021 at 10:45:21AM -0700, Dan Williams wrote: > > Ah, ok, we're missing a flush of the hotplug event handler after the > > link is up to make sure the hotplug handler does not see the Link Up. > > I'm not immediately seeing how the new proposal ensures that there is > > no Link Up event still in flight after DPC completes its work. > > Wouldn't it be required to throw away Link Up to Link Up transitions? > > If you look at the new code added to pciehp_ist() by my patch... > > atomic_and(~PCI_EXP_SLTSTA_DLLSC, &ctrl->pending_events); > if (pciehp_check_link_active(ctrl) > 0) > events &= ~PCI_EXP_SLTSTA_DLLSC; When you have a Surprise Link Down and without any DPC, the link trains back up. Aren't we expected to take the slot down and add it as if a remove and add happens? without this change if slot-status == ON_STATE, DLLSC means we would power the slot off. Then we check link_active and bring the slot back on isn't it?
