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Subject: Re: [PATCH v2] bluetooth: hci_sysfs: Ensure sysfs add/del is
 pre-empt safe
From: Marcel Holtmann <marcel@holtmann.org>
To: Roger Quadros <ext-roger.quadros@nokia.com>
Cc: linux-bluetooth@vger.kernel.org
In-Reply-To: <49F577D6.6090607@nokia.com>
References: <49F05193.7070609@nokia.com>
	 <1240486951.15894.5.camel@localhost.localdomain>
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Content-Type: text/plain
Date: Mon, 27 Apr 2009 05:06:53 -0700
Message-Id: <1240834013.997.1.camel@localhost.localdomain>
Mime-Version: 1.0
Sender: linux-bluetooth-owner@vger.kernel.org
List-ID: <linux-bluetooth.vger.kernel.org>

Hi Roger,

> > From: Roger Quadros <ext-roger.quadros@nokia.com>
> > Date: Thu, 23 Apr 2009 14:05:19 +0300
> > Subject: [PATCH v2] bluetooth: hci_sysfs: Ensure sysfs add/del is 
> > pre-empt safe
> > 
> > Uses different work_struct variables for add_conn() and del_conn(). Uses
> > single work queue instead of two for adding and deleting connections.
> > 
> > It eliminates the following error on a pre-emptible kernel.
> > 
> > [  204.358032] Unable to handle kernel NULL pointer dereference at
> > virtual address 0000000c
> > [  204.370697] pgd = c0004000
> > [  204.373443] [0000000c] *pgd=00000000
> > [  204.378601] Internal error: Oops: 17 [#1] PREEMPT
> > [  204.383361] Modules linked in: vfat fat rfcomm sco l2cap sd_mod
> > scsi_mod iphb pvr2d drm omaplfb ps
> > [  204.438537] CPU: 0    Not tainted  (2.6.28-maemo2 #1)
> > [  204.443664] PC is at klist_put+0x2c/0xb4
> > [  204.447601] LR is at klist_put+0x18/0xb4
> > [  204.451568] pc : [<c0270f08>]    lr : [<c0270ef4>]    psr: a0000113
> > [  204.451568] sp : cf1b3f10  ip : cf1b3f10  fp : cf1b3f2c
> > [  204.463104] r10: 00000000  r9 : 00000000  r8 : bf08029c
> > [  204.468353] r7 : c7869200  r6 : cfbe2690  r5 : c78692c8  r4 :
> > 00000001
> > [  204.474945] r3 : 00000001  r2 : cf1b2000  r1 : 00000001  r0 :
> > 00000000
> > [  204.481506] Flags: NzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM
> > Segment kernel
> > [  204.488861] Control: 10c5387d  Table: 887fc018  DAC: 00000017
> > [  204.494628] Process btdelconn (pid: 515, stack limit = 0xcf1b22e0)
> > 
> > Signed-off-by: Roger Quadros <ext-roger.quadros@nokia.com>
> > ---
> >  include/net/bluetooth/hci_core.h |    3 ++-
> >  net/bluetooth/hci_sysfs.c        |   37 
> > ++++++++++++++++---------------------
> >  2 files changed, 18 insertions(+), 22 deletions(-)
> > 
>
>   What is the fate of this patch?

the patch is part of bluetooth-testing.git and as soon as I have
debugged another issue (and hopefully fixed), I will send it to David
Miller for inclusion.

Regards

Marcel