linux-kernel - RE: core: workque: workqueue recursion when unplugging usb WCDMA modem on 2.6.32 kernel

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Message-ID: <ED2979D1CA1B3E4BB166ED9990088522765FF0@SJOAMSEXB01.AMERICAS.ROOT.PRI>
Date:	Thu, 22 Apr 2010 19:46:18 -0700
From:	"YuPing Luo" <YuPing.Luo@....com>
To:	Arve Hjønnevåg <arve@...roid.com>
Cc:	"Greg KH" <greg@...ah.com>, <linux-kernel@...r.kernel.org>,
	<linux-usb@...r.kernel.org>
Subject: RE: core: workque: workqueue recursion when unplugging usb WCDMA modem on 2.6.32 kernel

 From: Arve Hjønnevåg [mailto:arve@...roid.com] Sent: Friday, April 23, 2010 7:28 AM
> I don't think this is related to your console. I could easily
> reproduce your problem by killing rild (which uses both the binder and
> ttys). You may also what to find out why your rild is exiting.

I make the rild service stopped while vold daemon detect usb-modem unplugged.

>>  The recursion can be avoided if introducing one dedicated work queue
>> thread for binder 
> I just pushed a fix that does exactly that.
Good news, and just confused while the workqueue introduced in binder, why the tty_release() triggered by its work handler, the normal case looks like following:

(tty_release+0x1c/0x28)
[   68.068397] [<c021f16c>] (tty_release+0x0/0x28) from [<c01318f8>] (__fput+0xe0/0x210)
[   68.076177]  r5:00000008 r4:c69009c0
......
[   68.102362]  r7:00000006 r6:c69009c0 r5:c78a60c0 r4:c281e000
[   68.108026] [<c012f748>] (sys_close+0x0/0x110) from [<c0089f40>] (ret_fast_syscall+0x0/0x2c)
[   68.116453]  r7:00000006 r6:0002ac60 r5:00000010 r4:0002ef08
[   68.122068] ---[ end trace 6c2209be9c1c296c ]---
[   68.234009] option_release

Thanks
Yuping


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