USB-A port not powered up on AMD Ryzen

On Fedora 40, with FW 13 AMD, I have installed the USB-A expansion card on the left, the slot near the front (as advised, the port on the back supporting USB4 will consume more power).

After some time not using the port, if I plus an USB2 device (USB key, 4G modem), the device will not power up at all and will not be registered by the computer. It is as if the power pins do not provide the required 5V on that port.

However, if I take away the expansion card and put it back, then the USB2 device starts working again.

I suspect that there is something that puts the connector to sleep after some time not in use, to avoid drawing too much current. However, it does not correctly come back from sleep. Is this a known issue?

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This sounds like an issue i’ve faced on linux with powertop before. I think fedora uses like a power-profiles-daemon or TLP or something, but you can usually configure USB auto-suspend from inside the operating system. I would double check your services to see if powertop or tlp is running and then go to the arch wiki and see what the process is for disabling usb auto-suspend on them (or fedoras documentation on the power-profiles-daemon)

Edit:namely, my guess is the USB waking isn’t extending to the other end of the usb c to USB a expansion card, meaning that once the expansion chip goes to sleep, it can’t wake up without being reattached. Idk if that’s really what’s happening, but it sounds plausible

You’ve described it better than I could.

I thought the front left USB A had died, I took it out and tried it elsewhere and it was fine, reseated it and it started up again, this was after several power cycles etc.

Fedora 40 FW 13 AMD too