From: "alpha @ steudten Engineering" <alpha@steudten.com>
To: LKML <linux-kernel@vger.kernel.org>, luca.risolia@studio.unibo.it
Subject: Problem with sn9c102 webcam locks ..
Date: Wed, 18 Oct 2006 22:47:04 +0200 [thread overview]
Message-ID: <453692C8.50907@steudten.org> (raw)
Hi list
unplugging the webcam, the kernel 2.6.18 gives this output..
description: V4L2 driver for SN9C10x PC Camera Controllers
version: 1:1.27
license: GPL
vermagic: 2.6.18-1.2200self mod_unload PENTIUMM REGPARM gcc-4.1
depends: videodev,v4l2-common
usb 2-2: new full speed USB device using uhci_hcd and address 2
PM: Adding info for usb:2-2
PM: Adding info for No Bus:usbdev2.2_ep00
usb 2-2: configuration #1 chosen from 1 choice
PM: Adding info for usb:2-2:1.0
PM: Adding info for No Bus:usbdev2.2_ep81
PM: Adding info for No Bus:usbdev2.2_ep82
PM: Adding info for No Bus:usbdev2.2_ep83
Linux video capture interface: v2.00
sn9c102: V4L2 driver for SN9C10x PC Camera Controllers v1:1.27
usb 2-2: SN9C10[12] PC Camera Controller detected (vid/pid 0x0C45/0x6029)
usb 2-2: PAS106B image sensor detected
usb 2-2: Initialization succeeded
usb 2-2: V4L2 device registered as /dev/video0
usbcore: registered new driver sn9c102
=======================================================
[ INFO: possible circular locking dependency detected ]
2.6.18-1.2200self #1
-------------------------------------------------------
sn-webcam/3184 is trying to acquire lock:
(&cam->dev_mutex){--..}, at: [<c03261e6>] mutex_lock_interruptible+0x21/0x24
but task is already holding lock:
(videodev_lock){--..}, at: [<c0326512>] mutex_lock+0x21/0x24
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (videodev_lock){--..}:
[<c012da43>] __lock_acquire+0x82c/0x904
[<c012e083>] lock_acquire+0x4b/0x6c
[<c03263a4>] __mutex_lock_slowpath+0xb3/0x200
[<c0326512>] mutex_lock+0x21/0x24
[<f93f91a2>] video_register_device+0x9e/0x217 [videodev]
[<f9c76f42>] sn9c102_usb_probe+0x36e/0x4f2 [sn9c102]
[<c02a0bbc>] usb_probe_interface+0x5b/0x8b
[<c0267866>] driver_probe_device+0x45/0x92
[<c026798f>] __driver_attach+0x66/0x8f
[<c02672e5>] bus_for_each_dev+0x36/0x5b
[<c02677c1>] driver_attach+0x14/0x17
[<c0266fc5>] bus_add_driver+0x68/0x106
[<c0267c2f>] driver_register+0x78/0x7d
[<c02a09dd>] usb_register_driver+0x65/0xc6
[<f9396028>] 0xf9396028
[<c01341a1>] sys_init_module+0x1340/0x148b
[<c0102e17>] syscall_call+0x7/0xb
[<ffffffff>] 0xffffffff
-> #0 (&cam->dev_mutex){--..}:
[<c012d977>] __lock_acquire+0x760/0x904
[<c012e083>] lock_acquire+0x4b/0x6c
[<c0326024>] __mutex_lock_interruptible_slowpath+0xb3/0x254
[<c03261e6>] mutex_lock_interruptible+0x21/0x24
[<f9c766d9>] sn9c102_open+0x43/0x53e [sn9c102]
[<f93fb2e2>] video_open+0xba/0x135 [videodev]
[<c0167125>] chrdev_open+0xf3/0x123
[<c015e2ae>] __dentry_open+0xb9/0x187
[<c015e3ea>] nameidata_to_filp+0x1c/0x2e
[<c015e42a>] do_filp_open+0x2e/0x35
[<c015e471>] do_sys_open+0x40/0xb5
[<c015e512>] sys_open+0x16/0x18
[<c0102e17>] syscall_call+0x7/0xb
[<ffffffff>] 0xffffffff
other info that might help us debug this:
2 locks held by sn-webcam/3184:
#0: (videodev_lock){--..}, at: [<c0326512>] mutex_lock+0x21/0x24
#1: (sn9c102_disconnect){..--}, at: [<f9c766b1>] sn9c102_open+0x1b/0x53e [sn9c102]
stack backtrace:
[<c0103c87>] show_trace_log_lvl+0x12/0x25
[<c0103d6a>] show_trace+0xd/0x10
[<c0104532>] dump_stack+0x19/0x1b
[<c012d20c>] print_circular_bug_tail+0x59/0x64
[<c012d977>] __lock_acquire+0x760/0x904
[<c012e083>] lock_acquire+0x4b/0x6c
[<c0326024>] __mutex_lock_interruptible_slowpath+0xb3/0x254
[<c03261e6>] mutex_lock_interruptible+0x21/0x24
[<f9c766d9>] sn9c102_open+0x43/0x53e [sn9c102]
[<f93fb2e2>] video_open+0xba/0x135 [videodev]
[<c0167125>] chrdev_open+0xf3/0x123
[<c015e2ae>] __dentry_open+0xb9/0x187
[<c015e3ea>] nameidata_to_filp+0x1c/0x2e
[<c015e42a>] do_filp_open+0x2e/0x35
[<c015e471>] do_sys_open+0x40/0xb5
[<c015e512>] sys_open+0x16/0x18
[<c0102e17>] syscall_call+0x7/0xb
=======================
usb 2-2: USB disconnect, address 2
PM: Removing info for No Bus:usbdev2.2_ep81
PM: Removing info for No Bus:usbdev2.2_ep82
PM: Removing info for No Bus:usbdev2.2_ep83
usb 2-2: Disconnecting SN9C10x PC Camera...
usb 2-2: V4L2 device /dev/video0 deregistered
PM: Removing info for usb:2-2:1.0
PM: Removing info for No Bus:usbdev2.2_ep00
PM: Removing info for usb:2-2
Slab corruption: (Not tainted) start=e6fd417c, len=1024
Redzone: 0x5a2cf071/0x5a2cf071.
Last user: [<c029a4c2>](usb_release_dev+0x40/0x43)
[<c0103c87>] show_trace_log_lvl+0x12/0x25
[<c0103d6a>] show_trace+0xd/0x10
[<c0104532>] dump_stack+0x19/0x1b
[<c015b3a1>] check_poison_obj+0x6f/0x171
[<c015b4c8>] cache_alloc_debugcheck_after+0x25/0x135
[<c015c682>] kmem_cache_alloc+0x94/0xa0
[<c013f051>] audit_alloc+0x65/0xc4
[<c01161e2>] copy_process+0x56e/0x11a6
[<c0116e5c>] do_fork+0x42/0x112
[<c0101200>] sys_clone+0x25/0x2a
[<c0102e17>] syscall_call+0x7/0xb
=======================
170: 6b 6b 6b 6b 6b 6b 6b 6b 6a 6b 6b 6b 6b 6b 6b 6b
Single bit error detected. Probably bad RAM.
Run memtest86+ or a similar memory test tool.
Next obj: start=e6fd4588, len=1024
Redzone: 0x5a2cf071/0x5a2cf071.
Last user: [<c02cea08>](skb_release_data+0x80/0x84)
000: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
010: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
next reply other threads:[~2006-10-18 20:47 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-10-18 20:47 alpha @ steudten Engineering [this message]
2006-10-18 21:38 ` Problem with sn9c102 webcam locks Luca Risolia
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