これは 4.8 リリース候補で発生し、カーネルが安定したら修正されると思っていましたが、まだ問題があります。カーネルは USB コントローラーをランダムにリセットするか、それに似た動作をしているようです。基本的に、すべての USB デバイスがランダムに動作を停止し、システムを強制的に再起動して復帰させる必要がありますが、5 分ほど動作してから再び同じ動作を繰り返します。システムを使用できるよう 4.7.6 にロールバックしましたが、4.8 は USB で動作しないようです。これは syslog で見つけたもので、問題のログだと思います。
Oct 2 22:23:31 user-desktop kernel: [ 143.307247] ohci-pci 0000:00:12.0: HcDoneHead not written back; disabled
Oct 2 22:23:31 user-desktop kernel: [ 143.307251] ohci-pci 0000:00:12.0: HC died; cleaning up
Oct 2 22:23:31 user-desktop kernel: [ 143.307292] usb 10-1: USB disconnect, device number 2
Oct 2 22:23:31 user-desktop gdm-Xorg-:0[701]: (II) config/udev: removing device Logitech G700s Rechargeable Gaming Mouse
Oct 2 22:23:31 user-desktop gdm-Xorg-:0[701]: (II) evdev: Logitech G700s Rechargeable Gaming Mouse: Close
Oct 2 22:23:31 user-desktop gdm-Xorg-:0[701]: (II) UnloadModule: "evdev"
Oct 2 22:23:31 user-desktop acpid: input device has been disconnected, fd 4
Oct 2 22:23:31 user-desktop gdm-Xorg-:0[701]: (II) config/udev: removing device Logitech G700s Rechargeable Gaming Mouse
Oct 2 22:23:31 user-desktop pulseaudio[804]: Got POLLNVAL from ALSA
Oct 2 22:23:31 user-desktop pulseaudio[804]: Could not recover from POLLERR|POLLNVAL|POLLHUP with snd_pcm_prepare(): No such device
Oct 2 22:23:31 user-desktop kernel: [ 143.427525] usb 10-2: USB disconnect, device number 3
Oct 2 22:23:31 user-desktop gnome-session[720]: (gnome-settings-daemon:778): media-keys-plugin-WARNING **: Unable to get default sink
Oct 2 22:23:31 user-desktop gdm-Xorg-:0[701]: (II) evdev: Logitech G700s Rechargeable Gaming Mouse: Close
Oct 2 22:23:31 user-desktop gdm-Xorg-:0[701]: (II) UnloadModule: "evdev"
Oct 2 22:23:31 user-desktop acpid: input device has been disconnected, fd 15
Oct 2 22:23:31 user-desktop gdm-Xorg-:0[701]: (II) config/udev: removing device Logitech Logitech G933 Gaming Wireless Headset
Oct 2 22:23:31 user-desktop kernel: [ 143.483518] usb 10-4: USB disconnect, device number 4
Oct 2 22:23:31 user-desktop gdm-Xorg-:0[701]: (II) evdev: Logitech Logitech G933 Gaming Wireless Headset: Close
Oct 2 22:23:31 user-desktop gdm-Xorg-:0[701]: (II) UnloadModule: "evdev"
Oct 2 22:23:31 user-desktop gdm-Xorg-:0[701]: (II) config/udev: removing device Logitech USB Receiver
Oct 2 22:23:31 user-desktop gdm-Xorg-:0[701]: (II) evdev: Logitech USB Receiver: Close
Oct 2 22:23:31 user-desktop gdm-Xorg-:0[701]: (II) UnloadModule: "evdev"
Oct 2 22:23:31 user-desktop acpid: input device has been disconnected, fd 21
Oct 2 22:23:31 user-desktop gdm-Xorg-:0[701]: (II) config/udev: removing device Logitech USB Receiver
Oct 2 22:23:31 user-desktop kernel: [ 143.623574] usb 10-5: USB disconnect, device number 5
Oct 2 22:23:31 user-desktop gdm-Xorg-:0[701]: (II) evdev: Logitech USB Receiver: Close
Oct 2 22:23:31 user-desktop gdm-Xorg-:0[701]: (II) UnloadModule: "evdev"
Oct 2 22:23:31 user-desktop acpid: input device has been disconnected, fd 22
Oct 2 22:23:31 user-desktop gdm-Xorg-:0[701]: (II) config/udev: removing device Logitech Gaming Keyboard G910
Oct 2 22:23:31 user-desktop gdm-Xorg-:0[701]: (II) evdev: Logitech Gaming Keyboard G910: Close
Oct 2 22:23:31 user-desktop gdm-Xorg-:0[701]: (II) UnloadModule: "evdev"
Oct 2 22:23:31 user-desktop acpid: input device has been disconnected, fd 23
Oct 2 22:23:31 user-desktop gdm-Xorg-:0[701]: (II) config/udev: removing device Logitech Gaming Keyboard G910
Oct 2 22:23:31 user-desktop gdm-Xorg-:0[701]: (II) evdev: Logitech Gaming Keyboard G910: Close
Oct 2 22:23:31 user-desktop gdm-Xorg-:0[701]: (II) UnloadModule: "evdev"