hi, I'm seeing resets and re-enumerations on runtime-resume for one device a lot. It's a modem connected to the USB2642 Microchip (SMSC) USB2 hub, that's connected to an xhci HC. A remote wakeup *sometimes* makes the hub say "physically disconnected" during resume in hub_activate(), and thus sets reset_resume. Then the device comes up as low-speed device once, which again is not allowed during normal runtime resume, so would itself trigger a reset. The Hub and device is permanently connected on the PCB, so the hub is interpreting it in a wrong way. I found an email that describes what I see from Sarah Sharp in 2013 here: https://marc.info/?l=linux-usb&m=137754385421825&w=2 Where she says: "Occasionally, the host controller was sending the SoFs too soon on resume, and the device would interpret it as a low-speed chirp. The device would disconnect, and transform from a high speed device to a low speed device. I don't think increasing the 10 ms time out will help at all in this case, but you did ask what USB device disconnect scenarios I've seen." I can't find any reference to that bug yet. Has anyone experienced something (similar) and knows where I can at least try to work around that? I don't know Sarahs' current email, could we forward this question to her? thank a lot, martin
