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    SubjectRe: [BUG] object: is not initialized, yet kobject_put() is being called
    On 08/12/2010 09:04 AM, Markus Trippelsdorf wrote:
    > On Thu, Aug 12, 2010 at 02:57:57PM +0200, Jiri Kosina wrote:
    >> On Thu, 12 Aug 2010, Jiri Kosina wrote:
    >>>>>>>>> Guys, could you please send me your .config with which you are
    >>>>>>>>> experiencing the problem, so that I can try to reproduce it with it?
    >>>>>>>> Attached.
    >>>>>>> So I had to add support for HW of mine (SATA_VIA, PATA_VIA, disabled the
    >>>>>>> radeon firmware stuff, and, most importantly, enabled UHCI, which is what
    >>>>>>> is on machine I am using now for testing), and disconnect-connect cycle
    >>>>>>> works nicely:
    >>>>>>> usb 3-2: USB disconnect, address 3
    >>>>>>> usb 3-2: new low speed USB device using uhci_hcd and address 4
    >>>>>>> input: mouse USB mouse with wheel as /devices/pci0000:00/0000:00:10.1/usb3/3-2/3-2:1.0/input/input6
    >>>>>>> generic-usb 0003:05B8:3091.0004: input,hidraw0: USB HID v1.10 Mouse [mouse USB mouse with wheel] on usb-0000:00:10.1-2/input0
    >>>>>>> input: mouse USB mouse with wheel as /devices/pci0000:00/0000:00:10.1/usb3/3-2/3-2:1.1/input/input7
    >>>>>>> generic-usb 0003:05B8:3091.0005: input,hidraw1: USB HID v1.10 Keyboard [mouse USB mouse with wheel] on usb-0000:00:10.1-2/input1
    >>>>>>> so still no BUG from kobject refcounting, and the hidraw numbers are the
    >>>>>>> same. The major difference seems to be that I am using UHCI and you have
    >>>>>>> your HID devices connected through OHCI, is that correct?
    >>>>>> Correct. And I should add that it very easy to reproduce here; just
    >>>>>> disconnecting the usb receiver triggers the WARNING.
    >>>>> Disabling USB_HIDDEV in my .config solves the problem (there is no
    >>>>> WARNING anymore when disconnecting the receiver).
    >>>> Reverting bd25f4dd6972755579d0ea50d1a5ace2e9b00d1a with USB_HIDDEV
    >>>> enabled also solves the problem. So there must be a bug in that patch:
    >>>> commit bd25f4dd6972755579d0ea50d1a5ace2e9b00d1a
    >>>> Author: Arnd Bergmann<>
    >>>> Date: Sun Jul 11 15:34:05 2010 +0200
    >>>> HID: hiddev: use usb_find_interface, get rid of BKL
    >>>> This removes the private hiddev_table in the usbhid
    >>>> driver and changes it to use usb_find_interface
    >>>> instead.
    >>>> The advantage is that we can avoid the race between
    >>>> usb_register_dev and usb_open and no longer need the
    >>>> big kernel lock.
    >>>> This doesn't introduce race condition -- the intf pointer could be
    >>>> invalidated only in hiddev_disconnect() through usb_deregister_dev(),
    >>>> but that will block on minor_rwsem and not actually remove the device
    >>>> until usb_open().
    >>>> Signed-off-by: Arnd Bergmann<>
    >>>> Cc: Jiri Kosina<>
    >>>> Cc: "Greg Kroah-Hartman"<>
    >>>> Signed-off-by: Jiri Kosina<>
    >>> Thanks, I had my suspicion about this commit (that's why I asked to you
    >>> verify with CONFIG_USB_HIDDEV turned off as well).
    >>> Adding Arnd to CC and will look into it myself as well soon.
    >>> Arnd, the complete thread can be found at
    >> Could please those of you, who are able to reproduce the problem, verify
    >> whether the patch below (completely untested) makes everything behave
    >> again? Thanks.
    > Yes, everything behaves again. Thanks Jiri.

    Seconded. Works good. Thanks for your support Jiri.

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      Last update: 2010-08-12 15:11    [W:0.029 / U:1.672 seconds]
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