On Tue, 14 Dec 2010, Jeremy Roberson wrote: > Our company manufactures several USB devices and we use libUSB 1.0.8 to interact with these devices. Our devices function just fine when connected without the 7-Port USB Hub but almost as soon as the device is connected through the hub and we start reading/writing to the device, the system locks up completely and a hard boot is required. I should also note that this problem does occur with other newer USB hubs as well but I'm using this particular hub because I have it at home. This same problem occurs on Ubuntu 8.04 and Ubuntu 10.04 and probably others as it's looking like a kernel bug. If I use an old 4-Port Belkin non powered hub, this problem does not occur. This also does not happen with libUSB .1. > > Specifics are as follows. > > Linux Linux-Dev 2.6.32-26-generic-pae #47-Ubuntu SMP Wed Nov 17 16:14:46 UTC 2010 i686 GNU/Linux ... > Logging when the issue starts. Any logging with "NATIVESUPPORT" in the message is our native library logging. You can clearly see a kernel bug as well. > > Dec 2 16:07:34 Linux-Dev kernel: [ 2297.852041] usb 1-2: new high speed USB device using ehci_hcd and address 9 > Dec 2 16:07:35 Linux-Dev kernel: [ 2297.986504] usb 1-2: configuration #1 chosen from 1 choice > Dec 2 16:07:35 Linux-Dev kernel: [ 2297.986699] hub 1-2:1.0: USB hub found > Dec 2 16:07:35 Linux-Dev kernel: [ 2297.986875] hub 1-2:1.0: 7 ports detected ... > Dec 2 16:08:07 Linux-Dev kernel: [ 2330.065353] ------------[ cut here ]------------ > Dec 2 16:08:07 Linux-Dev kernel: [ 2330.065365] kernel BUG at /build/buildd/linux-2.6.32/mm/slub.c:2969! > Dec 2 16:08:07 Linux-Dev kernel: [ 2330.065372] invalid opcode: 0000 [#1] SMP > Dec 2 16:08:07 Linux-Dev kernel: [ 2330.065379] last sysfs file: /sys/devices/pci0000:00/0000:00:02.1/usb1/1-2/1-2.3/devnum > Dec 2 16:08:07 Linux-Dev kernel: [ 2330.065384] Modules linked in: nls_iso8859_1 nls_cp437 vfat fat rfcomm binfmt_misc ppdev sco bridge stp bnep l2cap vboxnetadp vboxnetflt vboxdrv snd_hda_codec_realtek snd_hda_intel snd_hda_codec snd_hwdep snd_pcm_oss snd_mixer_oss snd_pcm snd_seq_dummy snd_seq_oss snd_seq_midi snd_rawmidi snd_seq_midi_event snd_seq snd_timer snd_seq_device nvidia(P) cdc_acm fbcon tileblit font bitblit softcursor snd psmouse serio_raw agpgart vga16fb vgastate joydev k8temp btusb bluetooth soundcore snd_page_alloc lp i2c_nforce2 parport usb_storage usbhid hid ohci1394 ieee1394 floppy pata_amd sata_nv forcedeth > Dec 2 16:08:07 Linux-Dev kernel: [ 2330.065484] > Dec 2 16:08:07 Linux-Dev kernel: [ 2330.065492] Pid: 14301, comm: java Tainted: P (2.6.32-26-generic-pae #47-Ubuntu) > Dec 2 16:08:07 Linux-Dev kernel: [ 2330.065499] EIP: 0060:[<c0207895>] EFLAGS: 00010246 CPU: 1 > Dec 2 16:08:07 Linux-Dev kernel: [ 2330.065512] EIP is at kfree+0xf5/0x100 > Dec 2 16:08:07 Linux-Dev kernel: [ 2330.065517] EAX: 80000000 EBX: c27f4400 ECX: 00000000 EDX: 00000000 > Dec 2 16:08:07 Linux-Dev kernel: [ 2330.065522] ESI: 79520603 EDI: eb869c00 EBP: dec47ed4 ESP: dec47ebc > Dec 2 16:08:07 Linux-Dev kernel: [ 2330.065528] DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 > Dec 2 16:08:07 Linux-Dev kernel: [ 2330.065534] Process java (pid: 14301, ti=dec46000 task=e916bfc0 task.ti=dec46000) > Dec 2 16:08:07 Linux-Dev kernel: [ 2330.065539] Stack: > Dec 2 16:08:07 Linux-Dev kernel: [ 2330.065541] dec47ecc c035859d 79520603 79520603 00000000 eb869c00 dec47ee0 c0474158 > Dec 2 16:08:07 Linux-Dev kernel: [ 2330.065554] <0> 79520603 dec47f50 c047676d 00000000 00000001 c08e4f58 decd5b55 dec47f00 > Dec 2 16:08:07 Linux-Dev kernel: [ 2330.065567] <0> c0130dc8 dec47f14 c05b3b4f 4004550d e64555c0 dec47f34 eb869c98 00000918 > Dec 2 16:08:07 Linux-Dev kernel: [ 2330.065582] Call Trace: > Dec 2 16:08:07 Linux-Dev kernel: [ 2330.065594] [<c035859d>] ? kref_put+0x2d/0x60 > Dec 2 16:08:07 Linux-Dev kernel: [ 2330.065604] [<c0474158>] ? free_async+0x38/0x40 > Dec 2 16:08:07 Linux-Dev kernel: [ 2330.065613] [<c047676d>] ? usbdev_ioctl+0x75d/0xb80 > Dec 2 16:08:07 Linux-Dev kernel: [ 2330.065624] [<c0130dc8>] ? default_spin_lock_flags+0x8/0x10 > Dec 2 16:08:07 Linux-Dev kernel: [ 2330.065634] [<c05b3b4f>] ? _spin_lock_irqsave+0x2f/0x50 > Dec 2 16:08:07 Linux-Dev kernel: [ 2330.065643] [<c022108b>] ? vfs_ioctl+0x7b/0x90 > Dec 2 16:08:07 Linux-Dev kernel: [ 2330.065651] [<c0221319>] ? do_vfs_ioctl+0x79/0x310 > Dec 2 16:08:07 Linux-Dev kernel: [ 2330.065660] [<c0221f2c>] ? poll_select_set_timeout+0x6c/0x80 > Dec 2 16:08:07 Linux-Dev kernel: [ 2330.065668] [<c0221617>] ? sys_ioctl+0x67/0x80 > Dec 2 16:08:07 Linux-Dev kernel: [ 2330.065676] [<c01096c3>] ? sysenter_do_call+0x12/0x28 > Dec 2 16:08:07 Linux-Dev kernel: [ 2330.065681] Code: 8b 03 e9 78 ff ff ff 8b 3d b0 cb 7d c0 85 ff 0f 84 48 ff ff ff 8b 0f 83 c7 04 89 f2 89 d8 ff d1 8b 0f 85 c9 75 f1 e9 32 ff ff ff <0f> 0b eb fe 8d b4 26 00 00 00 00 55 89 e5 0f 1f 44 00 00 83 e8 > Dec 2 16:08:07 Linux-Dev kernel: [ 2330.065759] EIP: [<c0207895>] kfree+0xf5/0x100 SS:ESP 0068:dec47ebc > Dec 2 16:08:07 Linux-Dev kernel: [ 2330.065783] ---[ end trace 3549774142e4bf3e ]--- Great! Thanks for posting this. The very first thing is for you to verify that the same problem occurs with a more recent kernel, such as 2.6.36.2 or 2.6.37-rc5. It's quite possible that the problem has been fixed since 2.6.32 was released. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html