From: Dmitry Torokhov <dtor@insightbb.com>
To: "Luiz Fernando N. Capitulino" <lcapitulino@mandriva.com.br>
Cc: arjan@linux.intel.com, linux-kernel@vger.kernel.org
Subject: Re: LOCKDEP: input layer warning.
Date: Wed, 30 Aug 2006 19:29:35 -0400 [thread overview]
Message-ID: <200608301929.35456.dtor@insightbb.com> (raw)
In-Reply-To: <20060830171120.32466551@doriath.conectiva>
Hi Luiz,
On Wednesday 30 August 2006 16:11, Luiz Fernando N. Capitulino wrote:
>
> Hi Dmitry,
>
> A Mandriva user is getting the lockdep warning bellow when running an
> unpatched 2.6.18-rc5 kernel.
>
> But according to this thread:
>
> http://www.uwsg.iu.edu/hypermail/linux/kernel/0607.0/1598.html
>
> this was reported already, but not fixed.
I am still convinced that this is a false lockdep positive. The lock in
question is actuallt 2 separate mutextes, one on parent PS/2 device and
another on the child connected via synaptics' pass-through port.
>
> =============================================
> [ INFO: possible recursive locking detected ]
> ---------------------------------------------
> kseriod/187 is trying to acquire lock:
> (&ps2dev->cmd_mutex/1){--..}, at: [<c024b1da>] ps2_command+0x7b/0x2d6
>
> but task is already holding lock:
> (&ps2dev->cmd_mutex/1){--..}, at: [<c024b1da>] ps2_command+0x7b/0x2d6
>
> other info that might help us debug this:
> 4 locks held by kseriod/187:
> #0: (serio_mutex){--..}, at: [<c02bfd62>] mutex_lock+0x1c/0x1f
> #1: (&serio->drv_mutex){--..}, at: [<c02bfd62>] mutex_lock+0x1c/0x1f
> #2: (psmouse_mutex){--..}, at: [<c02bfd62>] mutex_lock+0x1c/0x1f
> #3: (&ps2dev->cmd_mutex/1){--..}, at: [<c024b1da>] ps2_command+0x7b/0x2d6
>
> stack backtrace:
> [<c010454c>] show_trace_log_lvl+0x58/0x152
> [<c0104b2c>] show_trace+0xd/0x10
> [<c0104c42>] dump_stack+0x19/0x1b
> [<c0135d2a>] __lock_acquire+0x755/0x973
> [<c013648b>] lock_acquire+0x4b/0x6c
> [<c02bfe28>] mutex_lock_nested+0xc3/0x209
> [<c024b1da>] ps2_command+0x7b/0x2d6
> [<c024fa91>] psmouse_sliced_command+0x1c/0x5a
> [<c0252f9a>] synaptics_pt_write+0x1e/0x44
> [<c024b0c7>] ps2_sendbyte+0x3e/0xd6
> [<c024b25b>] ps2_command+0xfc/0x2d6
> [<c024f6c4>] psmouse_probe+0x1d/0x68
> [<c025061a>] psmouse_connect+0xe8/0x20f
> [<c0248f76>] serio_connect_driver+0x1e/0x2e
> [<c0248f9c>] serio_driver_probe+0x16/0x18
> [<c022b08a>] driver_probe_device+0x45/0x92
> [<c022b0df>] __device_attach+0x8/0xa
> [<c022aa29>] bus_for_each_drv+0x3c/0x67
> [<c022b135>] device_attach+0x54/0x69
> [<c022a765>] bus_attach_device+0x16/0x2b
> [<c0229bcf>] device_add+0x1f8/0x2e3
> [<c0249a09>] serio_thread+0xd0/0x28f
> [<c0130a1d>] kthread+0xc3/0xf2
> [<c0101005>] kernel_thread_helper+0x5/0xb
> DWARF2 unwinder stuck at kernel_thread_helper+0x5/0xb
> Leftover inexact backtrace:
> [<c0104b2c>] show_trace+0xd/0x10
> [<c0104c42>] dump_stack+0x19/0x1b
> [<c0135d2a>] __lock_acquire+0x755/0x973
> [<c013648b>] lock_acquire+0x4b/0x6c
> [<c02bfe28>] mutex_lock_nested+0xc3/0x209
> [<c024b1da>] ps2_command+0x7b/0x2d6
> [<c024fa91>] psmouse_sliced_command+0x1c/0x5a
> [<c0252f9a>] synaptics_pt_write+0x1e/0x44
> [<c024b0c7>] ps2_sendbyte+0x3e/0xd6
> [<c024b25b>] ps2_command+0xfc/0x2d6
> [<c024f6c4>] psmouse_probe+0x1d/0x68
> [<c025061a>] psmouse_connect+0xe8/0x20f
> [<c0248f76>] serio_connect_driver+0x1e/0x2e
> [<c0248f9c>] serio_driver_probe+0x16/0x18
> [<c022b08a>] driver_probe_device+0x45/0x92
> [<c022b0df>] __device_attach+0x8/0xa
> [<c022aa29>] bus_for_each_drv+0x3c/0x67
> [<c022b135>] device_attach+0x54/0x69
> [<c022a765>] bus_attach_device+0x16/0x2b
> [<c0229bcf>] device_add+0x1f8/0x2e3
> [<c0249a09>] serio_thread+0xd0/0x28f
> [<c0130a1d>] kthread+0xc3/0xf2
> [<c0101005>] kernel_thread_helper+0x5/0xb
>
--
Dmitry
prev parent reply other threads:[~2006-08-30 23:29 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-08-30 20:11 LOCKDEP: input layer warning Luiz Fernando N. Capitulino
2006-08-30 23:29 ` Dmitry Torokhov [this message]
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