On Tue, 20 May 2025, Lukas Wunner wrote: > On Tue, May 20, 2025 at 12:44:38PM +0200, Lukas Wunner wrote: > > Link speed changes and device plug/unplug events are orthogonal, > > I don't think they should be mixed together in the same event. > > > > A link speed event can be signaled simultaneously to a plug event > > and then user space can decide in which type of event it's > > interested in. > > > > That also avoids the awkwardness of having N/A values for the > > link speed on unplug. > > After thinking about this some more: > > A link speed event could contain a "reason" field > which indicates why the link speed changed, > e.g. "hotplug", "autonomous", "thermal", "retrain", etc. > > In other words, instead of mixing the infomation for hotplug > and link speed events together in one event, a separate link > speed event could point to hotplug as one possible reason for > the new speed.
It will be somewhat challenging to link LBMS into what caused it, especially in cases where there is more than one LBMS following a single Link Retraining. Do you have opinion on should the event be only recorded from LBMS/LABS if the speed changed from the previous value? The speed should probably also be reported also for the first time (initial enumeration, hotplugging a new board). -- i.
