Thank you for link but I already found it and directions give there don't apply to my system. That forum discussion suggest to disable ehci_hcd but I don't have that modules loaded on my system. I have xhci_hcd loaded on my system but if I do: sudo rmmod xhci_hcd my USB mouse and keyboard stop working. The only USB connection that work are USB 3.0 where I connect mouse and keyboard. All others USB give errors if I connect something. My opinion is that the xhci_hcd module can manage only USB 3.0 hardware. This is my module list: Module Size Used by rfcomm 48294 0 bluetooth 179403 3 rfcomm parport_pc 37530 0 ppdev 17141 0 binfmt_misc 17646 1 dm_crypt 23761 0 usbhid 48081 0 hid 100109 1 usbhid snd_hda_codec_hdmi 33315 4 snd_hda_codec_realtek 321980 1 snd_hda_intel 34236 3 snd_seq_midi 13370 0 snd_rawmidi 30426 1 snd_seq_midi snd_hda_codec 108530 3 snd_hda_codec_hdmi,snd_hda_codec_realtek,snd_hda_intel snd_seq_midi_event 14899 1 snd_seq_midi snd_hwdep 13782 1 snd_hda_codec snd_seq 62088 2 snd_seq_midi,snd_seq_midi_event snd_pcm 98267 3 snd_hda_codec_hdmi,snd_hda_intel,snd_hda_codec snd_seq_device 14528 3 snd_seq_midi,snd_rawmidi,snd_seq snd_timer 30240 2 snd_seq,snd_pcm snd 68651 16 snd_hda_codec_hdmi,snd_hda_codec_realtek,snd_hda_intel,snd_rawmidi,snd_hda_codec,snd_hwdep,snd_seq,snd_pcm,snd_seq_device,snd_timer soundcore 12680 1 snd sp5100_tco 13787 0 lp 17868 0 snd_page_alloc 18572 2 snd_hda_intel,snd_pcm eeepc_wmi 12911 0 psmouse 70214 0 edac_core 54597 0 asus_wmi 25013 1 eeepc_wmi sparse_keymap 13995 1 asus_wmi k10temp 13159 0 i2c_piix4 13287 0 edac_mce_amd 23747 0 serio_raw 13294 0 parport 42788 3 parport_pc,ppdev,lp dm_mirror 22684 1 dm_region_hash 21033 1 dm_mirror dm_log 18788 3 dm_mirror,dm_region_hash e1000e 162398 0 pata_atiixp 13157 0 nouveau 757797 2 xhci_hcd 88842 0 ttm 77625 1 nouveau ahci 26150 4 drm_kms_helper 43171 1 nouveau libahci 31646 1 ahci drm 238528 4 nouveau,ttm,drm_kms_helper i2c_algo_bit 13436 1 nouveau mxm_wmi 12979 1 nouveau video 20027 1 nouveau wmi 19269 2 asus_wmi,mxm_wmi Maybe I need some other module laded to make all my USB connection to work? 2011/9/8 Matej Kenda