Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760037Ab0HLM6E (ORCPT ); Thu, 12 Aug 2010 08:58:04 -0400 Received: from cantor2.suse.de ([195.135.220.15]:45753 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753670Ab0HLM6B (ORCPT ); Thu, 12 Aug 2010 08:58:01 -0400 Date: Thu, 12 Aug 2010 14:57:57 +0200 (CEST) From: Jiri Kosina To: Markus Trippelsdorf Cc: Heinz Diehl , linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, linux-input@vger.kernel.org, Alan Ott , Arnd Bergmann Subject: Re: [BUG] object: is not initialized, yet kobject_put() is being called In-Reply-To: Message-ID: References: <20100810210941.GA7938@fritha.org> <20100810223215.GA1609@arch.tripp.de> <20100812091659.GA1591@arch.tripp.de> <20100812113624.GB1591@arch.tripp.de> <20100812114513.GA1584@arch.tripp.de> <20100812115657.GA1611@arch.tripp.de> User-Agent: Alpine 2.00 (LNX 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4599 Lines: 112 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 > http://lkml.org/lkml/2010/8/10/280 Could please those of you, who are able to reproduce the problem, verify whether the patch below (completely untested) makes everything behave again? Thanks. drivers/hid/usbhid/hiddev.c | 5 +++-- 1 files changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/hid/usbhid/hiddev.c b/drivers/hid/usbhid/hiddev.c index 254a003..0dcb79a 100644 --- a/drivers/hid/usbhid/hiddev.c +++ b/drivers/hid/usbhid/hiddev.c @@ -266,13 +266,15 @@ static int hiddev_open(struct inode *inode, struct file *file) { struct hiddev_list *list; struct usb_interface *intf; + struct hid_device *hid; struct hiddev *hiddev; int res; intf = usb_find_interface(&hiddev_driver, iminor(inode)); if (!intf) return -ENODEV; - hiddev = usb_get_intfdata(intf); + hid = usb_get_intfdata(intf); + hiddev = hid->hiddev; if (!(list = kzalloc(sizeof(struct hiddev_list), GFP_KERNEL))) return -ENOMEM; @@ -888,7 +890,6 @@ int hiddev_connect(struct hid_device *hid, unsigned int force) hid->hiddev = hiddev; hiddev->hid = hid; hiddev->exist = 1; - usb_set_intfdata(usbhid->intf, usbhid); retval = usb_register_dev(usbhid->intf, &hiddev_class); if (retval) { err_hid("Not able to get a minor for this device."); -- Jiri Kosina SUSE Labs, Novell Inc. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/