Hi Takashi, Thank you for the patch. On Friday 24 October 2014 10:10:20 Takashi Iwai wrote: > We've got a bug report at disconnecting a Webcam, where the kernel > spews warnings like below: > WARNING: CPU: 0 PID: 8385 at ../fs/sysfs/group.c:219 > sysfs_remove_group+0x87/0x90() sysfs group c0b2350c not found for kobject > 'event3' > CPU: 0 PID: 8385 Comm: queue2:src Not tainted 3.16.2-1.gdcee397-default #1 > Hardware name: ASUSTeK Computer INC. A7N8X-E/A7N8X-E, BIOS ASUS A7N8X-E > Deluxe ACPI BIOS Rev 1013 11/12/2004 c08d0705 ddc75cbc c0718c5b ddc75ccc > c024b654 c08c6d44 ddc75ce8 000020c1 c08d0705 000000db c03d1ec7 c03d1ec7 > 00000009 00000000 c0b2350c d62c9064 ddc75cd4 c024b6a3 00000009 ddc75ccc > c08c6d44 ddc75ce8 ddc75cfc c03d1ec7 Call Trace: > [<c0205ba6>] try_stack_unwind+0x156/0x170 > [<c02046f3>] dump_trace+0x53/0x180 > [<c0205c06>] show_trace_log_lvl+0x46/0x50 > [<c0204871>] show_stack_log_lvl+0x51/0xe0 > [<c0205c67>] show_stack+0x27/0x50 > [<c0718c5b>] dump_stack+0x3e/0x4e > [<c024b654>] warn_slowpath_common+0x84/0xa0 > [<c024b6a3>] warn_slowpath_fmt+0x33/0x40 > [<c03d1ec7>] sysfs_remove_group+0x87/0x90 > [<c05a2c54>] device_del+0x34/0x180 > [<c05e3989>] evdev_disconnect+0x19/0x50 > [<c05e06fa>] __input_unregister_device+0x9a/0x140 > [<c05e0845>] input_unregister_device+0x45/0x80 > [<f854b1d6>] uvc_delete+0x26/0x110 [uvcvideo] > [<f84d66f8>] v4l2_device_release+0x98/0xc0 [videodev] > [<c05a25bb>] device_release+0x2b/0x90 > [<c04ad8bf>] kobject_cleanup+0x6f/0x1a0 > [<f84d5453>] v4l2_release+0x43/0x70 [videodev] > [<c0372f31>] __fput+0xb1/0x1b0 > [<c02650c1>] task_work_run+0x91/0xb0 > [<c024d845>] do_exit+0x265/0x910 > [<c024df64>] do_group_exit+0x34/0xa0 > [<c025a76f>] get_signal_to_deliver+0x17f/0x590 > [<c0201b6a>] do_signal+0x3a/0x960 > [<c02024f7>] do_notify_resume+0x67/0x90 > [<c071ebb5>] work_notifysig+0x30/0x3b > [<b7739e60>] 0xb7739e5f > ---[ end trace b1e56095a485b631 ]--- > > The cause is that uvc_status_cleanup() is called after usb_put_*() in > uvc_delete(). usb_put_*() removes the sysfs parent and eventually > removes the children recursively, so the later device_del() can't find > its sysfs. The fix is simply rearrange the call orders in > uvc_delete() so that the child is removed before the parent. > > Bugzilla: https://bugzilla.suse.com/show_bug.cgi?id=897736 > Reported-and-tested-by: Martin Pluskal <mpluskal@xxxxxxxx> > Cc: <stable@xxxxxxxxxxxxxxx> > Signed-off-by: Takashi Iwai <tiwai@xxxxxxx> Acked-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> I've applied the patch to my tree and will send a pull request for the next kernel version. > --- > drivers/media/usb/uvc/uvc_driver.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/drivers/media/usb/uvc/uvc_driver.c > b/drivers/media/usb/uvc/uvc_driver.c index 7c8322d4fc63..3c07af96b30f > 100644 > --- a/drivers/media/usb/uvc/uvc_driver.c > +++ b/drivers/media/usb/uvc/uvc_driver.c > @@ -1623,12 +1623,12 @@ static void uvc_delete(struct uvc_device *dev) > { > struct list_head *p, *n; > > - usb_put_intf(dev->intf); > - usb_put_dev(dev->udev); > - > uvc_status_cleanup(dev); > uvc_ctrl_cleanup_device(dev); > > + usb_put_intf(dev->intf); > + usb_put_dev(dev->udev); > + > if (dev->vdev.dev) > v4l2_device_unregister(&dev->vdev); > #ifdef CONFIG_MEDIA_CONTROLLER -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
