I have two USB 2.0 compliant sound cards plugged into the USB ports of a Lenovo Thinkpad X61. Unplugging one of them (Focusrite Saffire USB 2.0) from a USB port into a powered USB 2.0 USB hub plugged into another of the laptop's USB port produces the following trace. I don't know if the culprit is the USB stack, sysfs/configfs or the ALSA subsystem. [348295.643626] usb 1-3: USB disconnect, device number 3 [348295.646368] ------------[ cut here ]------------ [348295.646386] WARNING: CPU: 0 PID: 973 at fs/sysfs/group.c:216 device_del+0x39/0x180() [348295.646392] sysfs group ffffffff8183df40 not found for kobject 'midiC1D0' [348295.646396] Modules linked in: rfcomm bnep bluetooth crc16 6lowpan_iphc snd_seq_midi snd_seq_midi_event snd_seq ioatdma dca coretemp usb_storage mmc_block fuse snd_usb_audio snd_usbmidi_lib snd_rawmidi snd_seq_device arc4 e1000e sdhci_pci firewire_ohci parport_pc parport snd_hda_codec_analog snd_hda_codec_generic sdhci yenta_socket iwl4965 pcmcia_core pcmcia_rsrc iwlegacy joydev firewire_core psmouse mmc_core i2c_i801 uhci_hcd ehci_pci ehci_hcd snd_hda_intel snd_hda_codec usbcore tpm_tis lpc_ich tpm mfd_core mei_me evdev usb_common i2c_dev snd_hwdep snd_pcm snd_timer snd crc_itu_t ptp acpi_cpufreq soundcore mac80211 cfg80211 pps_core loop [348295.646515] CPU: 0 PID: 973 Comm: khubd Not tainted 3.14.13-ST1NKP4D #1 [348295.646520] Hardware name: LENOVO 7673AQ7/7673AQ7, BIOS 7NETC2WW (2.22 ) 03/22/2011 [348295.646526] ffffffff81700a1c 00000000000000d8 ffffffff814a3e38 ffff8800b94cfaa8 [348295.646535] ffffffff8103cb72 ffff8800b9561000 ffff8800b9563400 0000000000000000 [348295.646543] ffff8800bb370400 0000000000000002 ffffffff8103cc55 ffffffff816fcb68 [348295.646552] Call Trace: [348295.646567] [<ffffffff814a3e38>] ? dump_stack+0x49/0x71 [348295.646583] [<ffffffff8103cb72>] ? warn_slowpath_common+0x82/0xb0 [348295.646591] [<ffffffff8103cc55>] ? warn_slowpath_fmt+0x45/0x50 [348295.646600] [<ffffffff813521e9>] ? device_del+0x39/0x180 [348295.646607] [<ffffffff81352339>] ? device_unregister+0x9/0x20 [348295.646614] [<ffffffff81352384>] ? device_destroy+0x34/0x40 [348295.646633] [<ffffffffa00ba29f>] ? snd_unregister_device+0x7f/0xd0 [snd] [348295.646644] [<ffffffffa025124e>] ? snd_rawmidi_dev_disconnect+0xce/0x100 [snd_rawmidi] [348295.646659] [<ffffffffa00c0192>] ? snd_device_disconnect+0x62/0x90 [snd] [348295.646672] [<ffffffffa00c025c>] ? snd_device_disconnect_all+0x3c/0x60 [snd] [348295.646687] [<ffffffffa00bb574>] ? snd_card_disconnect+0x124/0x1a0 [snd] [348295.646700] [<ffffffffa02e54e8>] ? usb_audio_disconnect+0x88/0x1c0 [snd_usb_audio] [348295.646722] [<ffffffffa015260e>] ? usb_unbind_interface+0x5e/0x1b0 [usbcore] [348295.646734] [<ffffffff813553e9>] ? __device_release_driver+0x79/0xf0 [348295.646742] [<ffffffff81355485>] ? device_release_driver+0x25/0x40 [348295.646750] [<ffffffff81354e11>] ? bus_remove_device+0xf1/0x130 [348295.646757] [<ffffffff813522b9>] ? device_del+0x109/0x180 [348295.646775] [<ffffffffa01501d5>] ? usb_disable_device+0x95/0x1f0 [usbcore] [348295.646791] [<ffffffffa014634f>] ? usb_disconnect+0x8f/0x190 [usbcore] [348295.646807] [<ffffffffa0149179>] ? hub_thread+0x539/0x13a0 [usbcore] [348295.646816] [<ffffffff810669f5>] ? sched_clock_local+0x15/0x80 [348295.646823] [<ffffffff81066c98>] ? sched_clock_cpu+0xb8/0xd0 [348295.646832] [<ffffffff81070730>] ? bit_waitqueue+0xb0/0xb0 [348295.646849] [<ffffffffa0148c40>] ? usb_port_resume+0x430/0x430 [usbcore] [348295.646865] [<ffffffffa0148c40>] ? usb_port_resume+0x430/0x430 [usbcore] [348295.646874] [<ffffffff8105973e>] ? kthread+0xce/0xf0 [348295.646882] [<ffffffff81059670>] ? kthread_create_on_node+0x1c0/0x1c0 [348295.646890] [<ffffffff814a8b7c>] ? ret_from_fork+0x7c/0xb0 [348295.646898] [<ffffffff81059670>] ? kthread_create_on_node+0x1c0/0x1c0 [348295.646904] ---[ end trace 40b1928d1136b91e ]--- [348295.646959] ------------[ cut here ]------------ [348295.646968] WARNING: CPU: 0 PID: 973 at fs/sysfs/group.c:216 device_del+0x39/0x180() [348295.646973] sysfs group ffffffff8183df40 not found for kobject 'pcmC1D0p' [348295.646976] Modules linked in: rfcomm bnep bluetooth crc16 6lowpan_iphc snd_seq_midi snd_seq_midi_event snd_seq ioatdma dca coretemp usb_storage mmc_block fuse snd_usb_audio snd_usbmidi_lib snd_rawmidi snd_seq_device arc4 e1000e sdhci_pci firewire_ohci parport_pc parport snd_hda_codec_analog snd_hda_codec_generic sdhci yenta_socket iwl4965 pcmcia_core pcmcia_rsrc iwlegacy joydev firewire_core psmouse mmc_core i2c_i801 uhci_hcd ehci_pci ehci_hcd snd_hda_intel snd_hda_codec usbcore tpm_tis lpc_ich tpm mfd_core mei_me evdev usb_common i2c_dev snd_hwdep snd_pcm snd_timer snd crc_itu_t ptp acpi_cpufreq soundcore mac80211 cfg80211 pps_core loop [348295.647093] CPU: 0 PID: 973 Comm: khubd Tainted: G W 3.14.13-ST1NKP4D #1 [348295.647097] Hardware name: LENOVO 7673AQ7/7673AQ7, BIOS 7NETC2WW (2.22 ) 03/22/2011 [348295.647102] ffffffff81700a1c 00000000000000d8 ffffffff814a3e38 ffff8800b94cfab8 [348295.647110] ffffffff8103cb72 ffff8800b9563000 ffff8800b9563400 0000000000000000 [348295.647118] ffff8800bb3bab50 0000000000000070 ffffffff8103cc55 ffffffff816fcb68 [348295.647126] Call Trace: [348295.647136] [<ffffffff814a3e38>] ? dump_stack+0x49/0x71 [348295.647146] [<ffffffff8103cb72>] ? warn_slowpath_common+0x82/0xb0 [348295.647154] [<ffffffff8103cc55>] ? warn_slowpath_fmt+0x45/0x50 [348295.647162] [<ffffffff813521e9>] ? device_del+0x39/0x180 [348295.647169] [<ffffffff81352339>] ? device_unregister+0x9/0x20 [348295.647177] [<ffffffff81352384>] ? device_destroy+0x34/0x40 [348295.647191] [<ffffffffa00ba29f>] ? snd_unregister_device+0x7f/0xd0 [snd] [348295.647207] [<ffffffffa00d4849>] ? snd_pcm_dev_disconnect+0x169/0x1e0 [snd_pcm] [348295.647221] [<ffffffffa00c0192>] ? snd_device_disconnect+0x62/0x90 [snd] [348295.647234] [<ffffffffa00c025c>] ? snd_device_disconnect_all+0x3c/0x60 [snd] [348295.647248] [<ffffffffa00bb574>] ? snd_card_disconnect+0x124/0x1a0 [snd] [348295.647260] [<ffffffffa02e54e8>] ? usb_audio_disconnect+0x88/0x1c0 [snd_usb_audio] [348295.647277] [<ffffffffa015260e>] ? usb_unbind_interface+0x5e/0x1b0 [usbcore] [348295.647288] [<ffffffff813553e9>] ? __device_release_driver+0x79/0xf0 [348295.647296] [<ffffffff81355485>] ? device_release_driver+0x25/0x40 [348295.647304] [<ffffffff81354e11>] ? bus_remove_device+0xf1/0x130 [348295.647311] [<ffffffff813522b9>] ? device_del+0x109/0x180 [348295.647328] [<ffffffffa01501d5>] ? usb_disable_device+0x95/0x1f0 [usbcore] [348295.647344] [<ffffffffa014634f>] ? usb_disconnect+0x8f/0x190 [usbcore] [348295.647360] [<ffffffffa0149179>] ? hub_thread+0x539/0x13a0 [usbcore] [348295.647367] [<ffffffff810669f5>] ? sched_clock_local+0x15/0x80 [348295.647374] [<ffffffff81066c98>] ? sched_clock_cpu+0xb8/0xd0 [348295.647383] [<ffffffff81070730>] ? bit_waitqueue+0xb0/0xb0 [348295.647399] [<ffffffffa0148c40>] ? usb_port_resume+0x430/0x430 [usbcore] [348295.647415] [<ffffffffa0148c40>] ? usb_port_resume+0x430/0x430 [usbcore] [348295.647423] [<ffffffff8105973e>] ? kthread+0xce/0xf0 [348295.647431] [<ffffffff81059670>] ? kthread_create_on_node+0x1c0/0x1c0 [348295.647438] [<ffffffff814a8b7c>] ? ret_from_fork+0x7c/0xb0 [348295.647446] [<ffffffff81059670>] ? kthread_create_on_node+0x1c0/0x1c0 [348295.647451] ---[ end trace 40b1928d1136b91f ]--- [348295.647937] ------------[ cut here ]------------ [348295.647952] WARNING: CPU: 0 PID: 973 at fs/sysfs/group.c:216 device_del+0x39/0x180() [348295.648062] sysfs group ffffffff8183df40 not found for kobject 'pcmC1D0c' [348295.648067] Modules linked in: rfcomm bnep bluetooth crc16 6lowpan_iphc snd_seq_midi snd_seq_midi_event snd_seq ioatdma dca coretemp usb_storage mmc_block fuse snd_usb_audio snd_usbmidi_lib snd_rawmidi snd_seq_device arc4 e1000e sdhci_pci firewire_ohci parport_pc parport snd_hda_codec_analog snd_hda_codec_generic sdhci yenta_socket iwl4965 pcmcia_core pcmcia_rsrc iwlegacy joydev firewire_core psmouse mmc_core i2c_i801 uhci_hcd ehci_pci ehci_hcd snd_hda_intel snd_hda_codec usbcore tpm_tis lpc_ich tpm mfd_core mei_me evdev usb_common i2c_dev snd_hwdep snd_pcm snd_timer snd crc_itu_t ptp acpi_cpufreq soundcore mac80211 cfg80211 pps_core loop [348295.648172] CPU: 0 PID: 973 Comm: khubd Tainted: G W 3.14.13-ST1NKP4D #1 [348295.648177] Hardware name: LENOVO 7673AQ7/7673AQ7, BIOS 7NETC2WW (2.22 ) 03/22/2011 [348295.648181] ffffffff81700a1c 00000000000000d8 ffffffff814a3e38 ffff8800b94cfab8 [348295.648190] ffffffff8103cb72 ffff8800b9563c00 ffff8800b9563400 0000000000000000 [348295.648198] ffff8800bb3bab50 0000000000000070 ffffffff8103cc55 ffffffff816fcb68 [348295.648206] Call Trace: [348295.648217] [<ffffffff814a3e38>] ? dump_stack+0x49/0x71 [348295.648228] [<ffffffff8103cb72>] ? warn_slowpath_common+0x82/0xb0 [348295.648236] [<ffffffff8103cc55>] ? warn_slowpath_fmt+0x45/0x50 [348295.648245] [<ffffffff813521e9>] ? device_del+0x39/0x180 [348295.648252] [<ffffffff81352339>] ? device_unregister+0x9/0x20 [348295.648259] [<ffffffff81352384>] ? device_destroy+0x34/0x40 [348295.648280] [<ffffffffa00ba29f>] ? snd_unregister_device+0x7f/0xd0 [snd] [348295.648296] [<ffffffffa00d4878>] ? snd_pcm_dev_disconnect+0x198/0x1e0 [snd_pcm] [348295.648310] [<ffffffffa00c0192>] ? snd_device_disconnect+0x62/0x90 [snd] [348295.648323] [<ffffffffa00c025c>] ? snd_device_disconnect_all+0x3c/0x60 [snd] [348295.648337] [<ffffffffa00bb574>] ? snd_card_disconnect+0x124/0x1a0 [snd] [348295.648351] [<ffffffffa02e54e8>] ? usb_audio_disconnect+0x88/0x1c0 [snd_usb_audio] [348295.648369] [<ffffffffa015260e>] ? usb_unbind_interface+0x5e/0x1b0 [usbcore] [348295.648380] [<ffffffff813553e9>] ? __device_release_driver+0x79/0xf0 [348295.648388] [<ffffffff81355485>] ? device_release_driver+0x25/0x40 [348295.648397] [<ffffffff81354e11>] ? bus_remove_device+0xf1/0x130 [348295.648404] [<ffffffff813522b9>] ? device_del+0x109/0x180 [348295.648421] [<ffffffffa01501d5>] ? usb_disable_device+0x95/0x1f0 [usbcore] [348295.648437] [<ffffffffa014634f>] ? usb_disconnect+0x8f/0x190 [usbcore] [348295.648453] [<ffffffffa0149179>] ? hub_thread+0x539/0x13a0 [usbcore] [348295.648461] [<ffffffff810669f5>] ? sched_clock_local+0x15/0x80 [348295.648468] [<ffffffff81066c98>] ? sched_clock_cpu+0xb8/0xd0 [348295.648477] [<ffffffff81070730>] ? bit_waitqueue+0xb0/0xb0 [348295.648493] [<ffffffffa0148c40>] ? usb_port_resume+0x430/0x430 [usbcore] [348295.648509] [<ffffffffa0148c40>] ? usb_port_resume+0x430/0x430 [usbcore] [348295.648517] [<ffffffff8105973e>] ? kthread+0xce/0xf0 [348295.648525] [<ffffffff81059670>] ? kthread_create_on_node+0x1c0/0x1c0 [348295.648534] [<ffffffff814a8b7c>] ? ret_from_fork+0x7c/0xb0 [348295.648541] [<ffffffff81059670>] ? kthread_create_on_node+0x1c0/0x1c0 [348295.648547] ---[ end trace 40b1928d1136b920 ]--- [348295.648603] ------------[ cut here ]------------ [348295.648612] WARNING: CPU: 0 PID: 973 at fs/sysfs/group.c:216 device_del+0x39/0x180() [348295.648617] sysfs group ffffffff8183df40 not found for kobject 'controlC1' [348295.648623] Modules linked in: rfcomm bnep bluetooth crc16 6lowpan_iphc snd_seq_midi snd_seq_midi_event snd_seq ioatdma dca coretemp usb_storage mmc_block fuse snd_usb_audio snd_usbmidi_lib snd_rawmidi snd_seq_device arc4 e1000e sdhci_pci firewire_ohci parport_pc parport snd_hda_codec_analog snd_hda_codec_generic sdhci yenta_socket iwl4965 pcmcia_core pcmcia_rsrc iwlegacy joydev firewire_core psmouse mmc_core i2c_i801 uhci_hcd ehci_pci ehci_hcd snd_hda_intel snd_hda_codec usbcore tpm_tis lpc_ich tpm mfd_core mei_me evdev usb_common i2c_dev snd_hwdep snd_pcm snd_timer snd crc_itu_t ptp acpi_cpufreq soundcore mac80211 cfg80211 pps_core loop [348295.648721] CPU: 0 PID: 973 Comm: khubd Tainted: G W 3.14.13-ST1NKP4D #1 [348295.648726] Hardware name: LENOVO 7673AQ7/7673AQ7, BIOS 7NETC2WW (2.22 ) 03/22/2011 [348295.648730] ffffffff81700a1c 00000000000000d8 ffffffff814a3e38 ffff8800b94cfab8 [348295.648738] ffffffff8103cb72 ffff8800b9562c00 ffff8800b9563400 00000000ffffffff [348295.648746] ffff8800ba3eb1b8 00000000fffffffa ffffffff8103cc55 ffffffff816fcb68 [348295.648754] Call Trace: [348295.648763] [<ffffffff814a3e38>] ? dump_stack+0x49/0x71 [348295.648772] [<ffffffff8103cb72>] ? warn_slowpath_common+0x82/0xb0 [348295.648780] [<ffffffff8103cc55>] ? warn_slowpath_fmt+0x45/0x50 [348295.648788] [<ffffffff813521e9>] ? device_del+0x39/0x180 [348295.648796] [<ffffffff81352339>] ? device_unregister+0x9/0x20 [348295.648803] [<ffffffff81352384>] ? device_destroy+0x34/0x40 [348295.648817] [<ffffffffa00ba29f>] ? snd_unregister_device+0x7f/0xd0 [snd] [348295.648831] [<ffffffffa00bd167>] ? snd_ctl_dev_disconnect+0x97/0xc0 [snd] [348295.648845] [<ffffffffa00c0192>] ? snd_device_disconnect+0x62/0x90 [snd] [348295.648858] [<ffffffffa00c025c>] ? snd_device_disconnect_all+0x3c/0x60 [snd] [348295.648872] [<ffffffffa00bb574>] ? snd_card_disconnect+0x124/0x1a0 [snd] [348295.648883] [<ffffffffa02e54e8>] ? usb_audio_disconnect+0x88/0x1c0 [snd_usb_audio] [348295.648901] [<ffffffffa015260e>] ? usb_unbind_interface+0x5e/0x1b0 [usbcore] [348295.648911] [<ffffffff813553e9>] ? __device_release_driver+0x79/0xf0 [348295.648919] [<ffffffff81355485>] ? device_release_driver+0x25/0x40 [348295.648927] [<ffffffff81354e11>] ? bus_remove_device+0xf1/0x130 [348295.648935] [<ffffffff813522b9>] ? device_del+0x109/0x180 [348295.648952] [<ffffffffa01501d5>] ? usb_disable_device+0x95/0x1f0 [usbcore] [348295.648968] [<ffffffffa014634f>] ? usb_disconnect+0x8f/0x190 [usbcore] [348295.648984] [<ffffffffa0149179>] ? hub_thread+0x539/0x13a0 [usbcore] [348295.648992] [<ffffffff810669f5>] ? sched_clock_local+0x15/0x80 [348295.648999] [<ffffffff81066c98>] ? sched_clock_cpu+0xb8/0xd0 [348295.649027] [<ffffffff81070730>] ? bit_waitqueue+0xb0/0xb0 [348295.649044] [<ffffffffa0148c40>] ? usb_port_resume+0x430/0x430 [usbcore] [348295.649061] [<ffffffffa0148c40>] ? usb_port_resume+0x430/0x430 [usbcore] [348295.649068] [<ffffffff8105973e>] ? kthread+0xce/0xf0 [348295.649076] [<ffffffff81059670>] ? kthread_create_on_node+0x1c0/0x1c0 [348295.649084] [<ffffffff814a8b7c>] ? ret_from_fork+0x7c/0xb0 [348295.649092] [<ffffffff81059670>] ? kthread_create_on_node+0x1c0/0x1c0 [348295.649097] ---[ end trace 40b1928d1136b921 ]--- [348295.649606] ------------[ cut here ]------------ [348295.649621] WARNING: CPU: 0 PID: 973 at fs/sysfs/group.c:216 device_del+0x39/0x180() [348295.649626] sysfs group ffffffff8183df40 not found for kobject 'card1' [348295.649629] Modules linked in: rfcomm bnep bluetooth crc16 6lowpan_iphc snd_seq_midi snd_seq_midi_event snd_seq ioatdma dca coretemp usb_storage mmc_block fuse snd_usb_audio snd_usbmidi_lib snd_rawmidi snd_seq_device arc4 e1000e sdhci_pci firewire_ohci parport_pc parport snd_hda_codec_analog snd_hda_codec_generic sdhci yenta_socket iwl4965 pcmcia_core pcmcia_rsrc iwlegacy joydev firewire_core psmouse mmc_core i2c_i801 uhci_hcd ehci_pci ehci_hcd snd_hda_intel snd_hda_codec usbcore tpm_tis lpc_ich tpm mfd_core mei_me evdev usb_common i2c_dev snd_hwdep snd_pcm snd_timer snd crc_itu_t ptp acpi_cpufreq soundcore mac80211 cfg80211 pps_core loop [348295.649734] CPU: 0 PID: 973 Comm: khubd Tainted: G W 3.14.13-ST1NKP4D #1 [348295.649739] Hardware name: LENOVO 7673AQ7/7673AQ7, BIOS 7NETC2WW (2.22 ) 03/22/2011 [348295.649743] ffffffff81700a1c 00000000000000d8 ffffffff814a3e38 ffff8800b94cfb68 [348295.649751] ffffffff8103cb72 ffff8800b9563400 ffff8800ba361430 ffff8800ba3eb228 [348295.649759] ffff8800ba3eb240 ffffffffa02fa0c8 ffffffff8103cc55 ffffffff816fcb68 [348295.649767] Call Trace: [348295.649778] [<ffffffff814a3e38>] ? dump_stack+0x49/0x71 [348295.649787] [<ffffffff8103cb72>] ? warn_slowpath_common+0x82/0xb0 [348295.649796] [<ffffffff8103cc55>] ? warn_slowpath_fmt+0x45/0x50 [348295.649804] [<ffffffff813521e9>] ? device_del+0x39/0x180 [348295.649812] [<ffffffff81352339>] ? device_unregister+0x9/0x20 [348295.649826] [<ffffffffa00bb591>] ? snd_card_disconnect+0x141/0x1a0 [snd] [348295.649838] [<ffffffffa02e54e8>] ? usb_audio_disconnect+0x88/0x1c0 [snd_usb_audio] [348295.649856] [<ffffffffa015260e>] ? usb_unbind_interface+0x5e/0x1b0 [usbcore] [348295.649867] [<ffffffff813553e9>] ? __device_release_driver+0x79/0xf0 [348295.649875] [<ffffffff81355485>] ? device_release_driver+0x25/0x40 [348295.649883] [<ffffffff81354e11>] ? bus_remove_device+0xf1/0x130 [348295.649891] [<ffffffff813522b9>] ? device_del+0x109/0x180 [348295.649908] [<ffffffffa01501d5>] ? usb_disable_device+0x95/0x1f0 [usbcore] [348295.649923] [<ffffffffa014634f>] ? usb_disconnect+0x8f/0x190 [usbcore] [348295.649939] [<ffffffffa0149179>] ? hub_thread+0x539/0x13a0 [usbcore] [348295.649947] [<ffffffff810669f5>] ? sched_clock_local+0x15/0x80 [348295.649954] [<ffffffff81066c98>] ? sched_clock_cpu+0xb8/0xd0 [348295.649963] [<ffffffff81070730>] ? bit_waitqueue+0xb0/0xb0 [348295.649979] [<ffffffffa0148c40>] ? usb_port_resume+0x430/0x430 [usbcore] [348295.649995] [<ffffffffa0148c40>] ? usb_port_resume+0x430/0x430 [usbcore] [348295.650027] [<ffffffff8105973e>] ? kthread+0xce/0xf0 [348295.650035] [<ffffffff81059670>] ? kthread_create_on_node+0x1c0/0x1c0 [348295.650043] [<ffffffff814a8b7c>] ? ret_from_fork+0x7c/0xb0 [348295.650050] [<ffffffff81059670>] ? kthread_create_on_node+0x1c0/0x1c0 [348295.650056] ---[ end trace 40b1928d1136b922 ]--- [348318.266441] usb 2-1.4: new high-speed USB device number 6 using ehci-pci [348318.352067] usb 2-1.4: New USB device found, idVendor=1235, idProduct=8008 [348318.352077] usb 2-1.4: New USB device strings: Mfr=1, Product=2, SerialNumber=0 [348318.352087] usb 2-1.4: Product: Saffire 6USB2.0 [348318.352093] usb 2-1.4: Manufacturer: Focusrite root@stinkpad:~# root@stinkpad:~# root@stinkpad:~# root@stinkpad:~# date Tue Jul 22 22:28:27 ART 2014 root@stinkpad:~# lsusb && lsusb -tv && lspci Bus 002 Device 002: ID 05e3:0608 Genesys Logic, Inc. Hub Bus 003 Device 002: ID 0483:2016 STMicroelectronics Fingerprint Reader Bus 005 Device 002: ID 4d46:0001 Musical Fidelity V-Link Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 002 Device 004: ID 05e3:0608 Genesys Logic, Inc. Hub Bus 002 Device 006: ID 1235:8008 Focusrite-Novation Saffire 6 Bus 002 Device 005: ID 0480:a006 Toshiba America Info. Systems, Inc. External Disk 1.5TB 3-2:1.0: No such file or directory 2-1.4:1.5: No such file or directory /: Bus 06.Port 1: Dev 1, Class=root_hub, Driver=uhci_hcd/2p, 12M /: Bus 05.Port 1: Dev 1, Class=root_hub, Driver=uhci_hcd/2p, 12M |__ Port 2: Dev 2, If 0, Class=audio, Driver=snd-usb-audio, 12M |__ Port 2: Dev 2, If 1, Class=audio, Driver=snd-usb-audio, 12M /: Bus 04.Port 1: Dev 1, Class=root_hub, Driver=uhci_hcd/2p, 12M /: Bus 03.Port 1: Dev 1, Class=root_hub, Driver=uhci_hcd/2p, 12M |__ Port 2: Dev 2, If 0, Class=vend., Driver=, 12M /: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=ehci-pci/4p, 480M |__ Port 1: Dev 2, If 0, Class=hub, Driver=hub/4p, 480M |__ Port 1: Dev 4, If 0, Class=hub, Driver=hub/4p, 480M |__ Port 1: Dev 5, If 0, Class=stor., Driver=usb-storage, 480M |__ Port 4: Dev 6, If 0, Class=audio, Driver=snd-usb-audio, 480M |__ Port 4: Dev 6, If 1, Class=audio, Driver=snd-usb-audio, 480M |__ Port 4: Dev 6, If 2, Class=audio, Driver=snd-usb-audio, 480M |__ Port 4: Dev 6, If 3, Class=audio, Driver=snd-usb-audio, 480M |__ Port 4: Dev 6, If 4, Class=audio, Driver=snd-usb-audio, 480M |__ Port 4: Dev 6, If 5, Class=app., Driver=, 480M /: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=ehci-pci/4p, 480M 00:00.0 Host bridge: Intel Corporation Mobile PM965/GM965/GL960 Memory Controller Hub (rev 0c) 00:02.0 VGA compatible controller: Intel Corporation Mobile GM965/GL960 Integrated Graphics Controller (primary) (rev 0c) 00:02.1 Display controller: Intel Corporation Mobile GM965/GL960 Integrated Graphics Controller (secondary) (rev 0c) 00:03.0 Communication controller: Intel Corporation Mobile PM965/GM965 MEI Controller (rev 0c) 00:03.2 IDE interface: Intel Corporation Mobile PM965/GM965 PT IDER Controller (rev 0c) 00:03.3 Serial controller: Intel Corporation Mobile PM965/GM965 KT Controller (rev 0c) 00:19.0 Ethernet controller: Intel Corporation 82566MM Gigabit Network Connection (rev 03) 00:1a.0 USB controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Controller #4 (rev 03) 00:1a.1 USB controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Controller #5 (rev 03) 00:1a.7 USB controller: Intel Corporation 82801H (ICH8 Family) USB2 EHCI Controller #2 (rev 03) 00:1b.0 Audio device: Intel Corporation 82801H (ICH8 Family) HD Audio Controller (rev 03) 00:1c.0 PCI bridge: Intel Corporation 82801H (ICH8 Family) PCI Express Port 1 (rev 03) 00:1c.1 PCI bridge: Intel Corporation 82801H (ICH8 Family) PCI Express Port 2 (rev 03) 00:1d.0 USB controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Controller #1 (rev 03) 00:1d.1 USB controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Controller #2 (rev 03) 00:1d.7 USB controller: Intel Corporation 82801H (ICH8 Family) USB2 EHCI Controller #1 (rev 03) 00:1e.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev f3) 00:1f.0 ISA bridge: Intel Corporation 82801HEM (ICH8M-E) LPC Interface Controller (rev 03) 00:1f.1 IDE interface: Intel Corporation 82801HM/HEM (ICH8M/ICH8M-E) IDE Controller (rev 03) 00:1f.2 SATA controller: Intel Corporation 82801HM/HEM (ICH8M/ICH8M-E) SATA Controller [AHCI mode] (rev 03) 00:1f.3 SMBus: Intel Corporation 82801H (ICH8 Family) SMBus Controller (rev 03) 03:00.0 Network controller: Intel Corporation PRO/Wireless 4965 AG or AGN [Kedron] Network Connection (rev 61) 05:00.0 CardBus bridge: Ricoh Co Ltd RL5c476 II (rev ba) 05:00.1 FireWire (IEEE 1394): Ricoh Co Ltd R5C832 IEEE 1394 Controller (rev 04) 05:00.2 SD Host controller: Ricoh Co Ltd R5C822 SD/SDIO/MMC/MS/MSPro Host Adapter (rev 21) root@stinkpad:~# root@stinkpad:~# uname -a Linux stinkpad 3.14.13-ST1NKP4D #1 SMP PREEMPT Fri Jul 18 19:54:58 ART 2014 x86_64 Intel(R) Core(TM)2 Duo CPU T7100 @ 1.80GHz GenuineIntel GNU/Linux root@stinkpad:~#
Could you check whether the patch below fixes the problem?
Created attachment 156631 [details] Test fix patch
Created attachment 156651 [details] trace before applying Takashi's patch to 3.14.23
Created attachment 156741 [details] output after applying Takashi's patch to 3.14.23
Thank you Takashi, the patch fixes the issue in 3.14.23. What may I do to help?
Good to hear! Then I'm going to queue this fix to sound git tree so that it will be pulled into 3.18-rc4. Then it'll be backported to each stable kernel eventually.
brilliant! Thank you!
The fix was merged into 3.18-rc4.