Isso aconteceu no release candidate 4.8 e pensei que seria corrigido quando o kernel ficasse estável, mas ainda estou tendo o problema. O kernel parece redefinir aleatoriamente meu controlador USB ou fazer algo nesse sentido. Basicamente, todos os meus dispositivos USB param de funcionar aleatoriamente e eu tenho que forçar a reinicialização do sistema para que eles voltem, apenas para que funcionem por cerca de 5 minutos antes de fazê-lo novamente. Voltei para o 4.7.6 para poder usar meu sistema, mas o 4.8 simplesmente não parece querer funcionar com USB. Isto é o que encontrei no syslog e acho que é um registro do problema.
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"