使用主板的 USB 2.0 连接的设备在 Ubuntu 14.04 中无法工作，但它们在 GRUB 2 中可以正常工作。
dmesg当我连接键盘时，会吐出类似这样的内容：
usb 7-3: new full-speed USB device number 6 using ohci-pci
usb 7-3: device descriptor read/64, error -32
usb 7-3: device not accepting address 6, error -32
usb 7-3: new full-speed USB device number 7 using ohci-pci
usb 7-3: device not accepting address 7, error -32
usb 7-3: new full-speed USB device number 8 using ohci-pci
usb 7-3: device not accepting address 8, error -32
usb 7-3: new full-speed USB device number 7 using ohci-pci
usb 7-3: device descriptor read/8, error -32
usb 7-3: device descriptor read/all, error -32
usb usb7-port3: unable to enumerate USB device
将同一个键盘连接到主板的 USB 3.0 可以正常工作。
答案1
我需要启用输入/输出内存管理单元 (IOMMU)在 BIOS 中。