From: Greg KH <greg@kroah.com>
To: Claudio Scordino <claudio@evidence.eu.com>
Cc: Alan Cox <alan@linux.intel.com>,
Nicolas Ferre <nicolas.ferre@atmel.com>,
Linux Kernel <linux-kernel@vger.kernel.org>,
"linux-serial@vger.kernel.org" <linux-serial@vger.kernel.org>,
Dave Bender <codehero@gmail.com>
Subject: Re: [PATCH] atmel_serial: fix spinlock lockup in RS485 code
Date: Thu, 15 Dec 2011 10:58:14 -0800 [thread overview]
Message-ID: <20111215185814.GD18791@kroah.com> (raw)
In-Reply-To: <4EE9D44A.6010300@evidence.eu.com>
On Thu, Dec 15, 2011 at 12:04:42PM +0100, Claudio Scordino wrote:
> Il 15/12/2011 11:00, Nicolas Ferre ha scritto:
> >On 12/15/2011 09:47 AM, Claudio Scordino :
> >>Hi all.
> >>
> >>We have encountered a spinlock lockup in the RS485 part of the
> >>atmel_serial driver.
> >>
> >>Here is the trace:
> >>
> >>[ 68.030000] BUG: spinlock lockup on CPU#0, dnp_master/244, c07e82c0
> >>[ 68.040000] [<c002a790>] (unwind_backtrace+0x0/0xf0) from
> >>[<c012f8f0>] (do_raw_spin_lock+0x10c/0x148)
> >>[ 68.050000] [<c012f8f0>] (do_raw_spin_lock+0x10c/0x148) from
> >>[<c015152c>] (atmel_tasklet_func+0x10/0x708)
> >>[ 68.060000] [<c015152c>] (atmel_tasklet_func+0x10/0x708) from
> >>[<c003bfd4>] (tasklet_action+0x8c/0xf4)
> >>[ 68.070000] [<c003bfd4>] (tasklet_action+0x8c/0xf4) from [<c003c630>]
> >>(__do_softirq+0xa4/0x180)
> >>[ 68.080000] [<c003c630>] (__do_softirq+0xa4/0x180) from [<c003c764>]
> >>(irq_exit+0x58/0xb0)
> >>[ 68.090000] [<c003c764>] (irq_exit+0x58/0xb0) from [<c0021084>]
> >>(asm_do_IRQ+0x84/0xa4)
> >>[ 68.100000] [<c0021084>] (asm_do_IRQ+0x84/0xa4) from [<c002622c>]
> >>(__irq_svc+0x4c/0x98)
> >>[ 68.110000] Exception stack(0xc341fdc8 to 0xc341fe10)
> >>[ 68.110000] fdc0: c07e82c0 00000000 00000200
> >>c4818000 c341fe10 c07e82c0
> >>[ 68.120000] fde0: 00000000 c07e82c0 c38d3318 c341e000 bebcee00
> >>010a0b60 c07e83fc c341fe10
> >>[ 68.130000] fe00: c0151d54 c023d9c0 60000013 ffffffff
> >>[ 68.140000] [<c002622c>] (__irq_svc+0x4c/0x98) from [<c023d9c0>]
> >>(_raw_spin_unlock+0x0/0x48)
> >>[ 68.140000] [<c023d9c0>] (_raw_spin_unlock+0x0/0x48) from
> >>[<00000000>] ( (null))
> >>
> >>The soft lockup occurs later
> >>
> >>[ 126.750000] BUG: soft lockup - CPU#0 stuck for 61s! [dnp_master:244]
> >>[ 126.750000] irq event stamp: 0
> >>[ 126.750000] hardirqs last enabled at (0): [< (null)>] (null)
> >>[ 126.750000] hardirqs last disabled at (0): [<c0035e30>]
> >>copy_process+0x308/0xe78
> >>[ 126.750000] softirqs last enabled at (0): [<c0035e30>]
> >>copy_process+0x308/0xe78
> >>[ 126.750000] softirqs last disabled at (0): [< (null)>] (null)
> >>
> >>
> >>The following patch (already tested by Dave, who also reported the bug)
> >>fixes the problem.
> >>
> >>Regards,
> >>
> >> Claudio
> >>
> >>
> >>
> >>
> >>Subject: atmel_serial: fix spinlock lockup in RS485 code
> >>
> >>Patch to fix a spinlock lockup in the driver that sometimes happens when
> >>the
> >>tasklet starts.
> >>
> >>Signed-off-by: Claudio Scordino<claudio@evidence.eu.com>
> >>Signed-off-by: Dave Bender<codehero@gmail.com>
> >>Tested-by: Dave Bender<codehero@gmail.com>
> >
> >Acked-by: Nicolas Ferre<nicolas.ferre@atmel.com>
> >
> >Claudio, can you please send the patch to Alan with my "Acked-by" and an
> >addition to Linux stable just after the signature lines:
> >
> >Cc: stable<stable@kernel.org>
That address has been invalid since August, please use
stable@vger.kernel.org now.
> Dear Alan,
>
> here is the patch with all the acked-bys.
I'll take care of this.
thanks,
greg k-h
next prev parent reply other threads:[~2011-12-15 19:03 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-15 8:47 [PATCH] atmel_serial: fix spinlock lockup in RS485 code Claudio Scordino
2011-12-15 10:00 ` Nicolas Ferre
2011-12-15 11:04 ` Claudio Scordino
2011-12-15 18:58 ` Greg KH [this message]
2011-12-16 14:08 ` Claudio Scordino
2011-12-15 10:22 ` Alan Cox
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