* [PATCH] atmel_serial: fix spinlock lockup in RS485 code
@ 2011-12-15 8:47 Claudio Scordino
2011-12-15 10:00 ` Nicolas Ferre
2011-12-15 10:22 ` Alan Cox
0 siblings, 2 replies; 6+ messages in thread
From: Claudio Scordino @ 2011-12-15 8:47 UTC (permalink / raw)
To: Nicolas Ferre, Alan Cox
Cc: Linux Kernel, linux-serial@vger.kernel.org, Dave Bender
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>
---
drivers/tty/serial/atmel_serial.c | 5 +++--
1 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index 4c823f3..90c8e3a 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -212,8 +212,9 @@ void atmel_config_rs485(struct uart_port *port, struct serial_rs485 *rs485conf)
{
struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
unsigned int mode;
+ unsigned long flags;
- spin_lock(&port->lock);
+ spin_lock_irqsave(&port->lock, flags);
/* Disable interrupts */
UART_PUT_IDR(port, atmel_port->tx_done_mask);
@@ -244,7 +245,7 @@ void atmel_config_rs485(struct uart_port *port, struct serial_rs485 *rs485conf)
/* Enable interrupts */
UART_PUT_IER(port, atmel_port->tx_done_mask);
- spin_unlock(&port->lock);
+ spin_unlock_irqrestore(&port->lock, flags);
}
--
1.7.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] atmel_serial: fix spinlock lockup in RS485 code
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 10:22 ` Alan Cox
1 sibling, 1 reply; 6+ messages in thread
From: Nicolas Ferre @ 2011-12-15 10:00 UTC (permalink / raw)
To: Claudio Scordino
Cc: Alan Cox, Linux Kernel, linux-serial@vger.kernel.org, Dave Bender
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>
Thanks, best regards,
> ---
> drivers/tty/serial/atmel_serial.c | 5 +++--
> 1 files changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/tty/serial/atmel_serial.c
> b/drivers/tty/serial/atmel_serial.c
> index 4c823f3..90c8e3a 100644
> --- a/drivers/tty/serial/atmel_serial.c
> +++ b/drivers/tty/serial/atmel_serial.c
> @@ -212,8 +212,9 @@ void atmel_config_rs485(struct uart_port *port,
> struct serial_rs485 *rs485conf)
> {
> struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
> unsigned int mode;
> + unsigned long flags;
>
> - spin_lock(&port->lock);
> + spin_lock_irqsave(&port->lock, flags);
>
> /* Disable interrupts */
> UART_PUT_IDR(port, atmel_port->tx_done_mask);
> @@ -244,7 +245,7 @@ void atmel_config_rs485(struct uart_port *port,
> struct serial_rs485 *rs485conf)
> /* Enable interrupts */
> UART_PUT_IER(port, atmel_port->tx_done_mask);
>
> - spin_unlock(&port->lock);
> + spin_unlock_irqrestore(&port->lock, flags);
>
> }
>
--
Nicolas Ferre
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] atmel_serial: fix spinlock lockup in RS485 code
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 10:22 ` Alan Cox
1 sibling, 0 replies; 6+ messages in thread
From: Alan Cox @ 2011-12-15 10:22 UTC (permalink / raw)
To: Claudio Scordino
Cc: Nicolas Ferre, Linux Kernel, linux-serial@vger.kernel.org,
Dave Bender
On Thu, 15 Dec 2011 09:47:43 +0100
Claudio Scordino <claudio@evidence.eu.com> wrote:
> 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: Alan Cox <alan@linux.intel.com>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] atmel_serial: fix spinlock lockup in RS485 code
2011-12-15 10:00 ` Nicolas Ferre
@ 2011-12-15 11:04 ` Claudio Scordino
2011-12-15 18:58 ` Greg KH
0 siblings, 1 reply; 6+ messages in thread
From: Claudio Scordino @ 2011-12-15 11:04 UTC (permalink / raw)
To: Alan Cox
Cc: Nicolas Ferre, Linux Kernel, linux-serial@vger.kernel.org,
Dave Bender
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>
Dear Alan,
here is the patch with all the acked-bys.
Many thanks,
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>
Acked-by: Alan Cox <alan@linux.intel.com>
Cc: stable <stable@kernel.org>
---
drivers/tty/serial/atmel_serial.c | 5 +++--
1 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index 4c823f3..90c8e3a 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -212,8 +212,9 @@ void atmel_config_rs485(struct uart_port *port, struct serial_rs485 *rs485conf)
{
struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
unsigned int mode;
+ unsigned long flags;
- spin_lock(&port->lock);
+ spin_lock_irqsave(&port->lock, flags);
/* Disable interrupts */
UART_PUT_IDR(port, atmel_port->tx_done_mask);
@@ -244,7 +245,7 @@ void atmel_config_rs485(struct uart_port *port, struct serial_rs485 *rs485conf)
/* Enable interrupts */
UART_PUT_IER(port, atmel_port->tx_done_mask);
- spin_unlock(&port->lock);
+ spin_unlock_irqrestore(&port->lock, flags);
}
--
1.7.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] atmel_serial: fix spinlock lockup in RS485 code
2011-12-15 11:04 ` Claudio Scordino
@ 2011-12-15 18:58 ` Greg KH
2011-12-16 14:08 ` Claudio Scordino
0 siblings, 1 reply; 6+ messages in thread
From: Greg KH @ 2011-12-15 18:58 UTC (permalink / raw)
To: Claudio Scordino
Cc: Alan Cox, Nicolas Ferre, Linux Kernel,
linux-serial@vger.kernel.org, Dave Bender
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
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] atmel_serial: fix spinlock lockup in RS485 code
2011-12-15 18:58 ` Greg KH
@ 2011-12-16 14:08 ` Claudio Scordino
0 siblings, 0 replies; 6+ messages in thread
From: Claudio Scordino @ 2011-12-16 14:08 UTC (permalink / raw)
To: Greg KH
Cc: Alan Cox, Nicolas Ferre, Linux Kernel,
linux-serial@vger.kernel.org, Dave Bender, stable
Il 15/12/2011 19:58, Greg KH ha scritto:
> 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.
Hi Greg,
here is the patch with the right address.
Many thanks for taking care of it.
Best 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>
Acked-by: Alan Cox <alan@linux.intel.com>
Cc: stable <stable@vger.kernel.org>
---
drivers/tty/serial/atmel_serial.c | 5 +++--
1 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index 4c823f3..90c8e3a 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -212,8 +212,9 @@ void atmel_config_rs485(struct uart_port *port, struct serial_rs485 *rs485conf)
{
struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
unsigned int mode;
+ unsigned long flags;
- spin_lock(&port->lock);
+ spin_lock_irqsave(&port->lock, flags);
/* Disable interrupts */
UART_PUT_IDR(port, atmel_port->tx_done_mask);
@@ -244,7 +245,7 @@ void atmel_config_rs485(struct uart_port *port, struct serial_rs485 *rs485conf)
/* Enable interrupts */
UART_PUT_IER(port, atmel_port->tx_done_mask);
- spin_unlock(&port->lock);
+ spin_unlock_irqrestore(&port->lock, flags);
}
--
1.7.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
end of thread, other threads:[~2011-12-16 14:16 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
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
2011-12-16 14:08 ` Claudio Scordino
2011-12-15 10:22 ` Alan Cox
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