On Fri, Mar 18, 2022 at 03:51:21PM +0100, Lukas Wunner wrote: > On Fri, Mar 18, 2022 at 02:08:16PM +0000, Robin Murphy wrote: > > OK, so do we have any realistic options for identifying the correct PCI > > devices, if USB4 PCIe adapters might be anywhere relative to their > > associated NHI? Short of maintaining a list of known IDs, the only thought I > > have left is that if we walk the whole PCI segment looking specifically for > > hotplug-capable Gen1 ports, any system modern enough to have Thunderbolt is > > *probably* not going to have any real PCIe Gen1 hotplug slots, so maybe > > false negatives might be tolerable, but it still feels like a bit of a > > sketchy heuristic. > > The Thunderbolt Device ROM contains the PCI slot number, so you can > correlate the Thunderbolt switch ports with PCIe downstream ports > and know exactly where PCIe tunnels are terminated. [...] > I implemented that in 2018, so it won't apply cleanly to current > mainline. But I kept forward-porting it on my private branch and > could push that to GitHub if anyone is interested. FWIW, here's the most recent forward-port I've done: https://github.com/l1k/linux/commits/thunderbolt_correlate_5.13
