Good day, all, and a happy new year. I have recently installed OpenSUSE Leap 42.3 on my father’s computer, and one of very few unexpected behaviours comes from the USB 2.0 ports. They do not work once it is booted into OpenSUSE. They work well in the BIOS (Gigabyte GA990FX-Gaming motherboard), and in windows, but not once booted into Linux. The 3.0 are normal. I did some searching online and found some mention of the IOMMU controller on Gigabyte AMD motherboards having something to do with this, and indeed, when I enabled the IOMMU controller in the BIOS, the USB 2.0 ports functioned as expected, but both the USB 3.0 ports and the network card became non-functional. Under YAST’s hardware probe, all of the USB ports show up as either XHCI or EHCI root hubs, so I decided to mess around with the XHCI and EHCI handoff settings in BIOS, and I could find no configuration that made any difference to the USB situation.
The hardware is all relatively recent; AMD FX 6300 CPU, 32GB DDR3 RAM, 120GB SSD boot disk, and as mentioned, a Gigabyte GA990FX-Gaming motherboard.
I am grateful for your taking the time to read this, and will be yet more so for any advice which is offered.