[PATCH] ARM: hw_breakpoint: Do not use __cpuinitdata for dbg_cpu_pm_nb

[PATCH] ARM: hw_breakpoint: Do not use __cpuinitdata for dbg_cpu_pm_nb

[Bastian Hecht]

We must not declare dbg_cpu_pm_nb as __cpuinitdata as we need it after
system initialization for Suspend and CPUIdle.

This was done in commit 9a6eb310eaa5336b89a27a0bbb78da4bba35f6f1
ARM: hw_breakpoint: Debug powerdown support for self-hosted debug

Signed-off-by: Bastian Hecht <hechtb+renesas@gmail.com>
---
Hi,

I've experienced a kernel oops while working on Suspend-To-Ram and CPUIdle
on the Armadillo800EVA from Renesas. After echo mem >/sys/power/state I get:

Unable to handle kernel paging request at virtual address e7fddef0
PC is at 0xe7fddef0
LR is at notifier_call_chain+0x40/0x70

I've bisected the kernel to the commit 9a6eb310eaa5336b89a27a0bbb78da4bba35f6f1

    ARM: hw_breakpoint: Debug powerdown support for self-hosted debug

and succeeded to fix it by removing the __cpuinitdata tag.

Cheers,

 Bastian

 arch/arm/kernel/hw_breakpoint.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/kernel/hw_breakpoint.c b/arch/arm/kernel/hw_breakpoint.c
index 96093b7..8eb67bc 100644
--- a/arch/arm/kernel/hw_breakpoint.c
+++ b/arch/arm/kernel/hw_breakpoint.c
@@ -1043,7 +1043,7 @@ static int dbg_cpu_pm_notify(struct notifier_block *self, unsigned long action,
 	return NOTIFY_OK;
 }
 
-static struct notifier_block __cpuinitdata dbg_cpu_pm_nb = {
+static struct notifier_block dbg_cpu_pm_nb = {
 	.notifier_call = dbg_cpu_pm_notify,
 };
 
-- 
1.7.9.5

[PATCH] ARM: hw_breakpoint: Do not use __cpuinitdata for dbg_cpu_pm_nb

[Will Deacon]

On Wed, Apr 10, 2013 at 11:04:38AM +0100, Bastian Hecht wrote:
> We must not declare dbg_cpu_pm_nb as __cpuinitdata as we need it after
> system initialization for Suspend and CPUIdle.
> 
> This was done in commit 9a6eb310eaa5336b89a27a0bbb78da4bba35f6f1
> ARM: hw_breakpoint: Debug powerdown support for self-hosted debug
> 
> Signed-off-by: Bastian Hecht <hechtb+renesas@gmail.com>

Thanks Bastian, I'll take this into my tree.

Will

[PATCH] ARM: hw_breakpoint: Do not use __cpuinitdata for dbg_cpu_pm_nb

[Bastian Hecht]

2013/4/10 Will Deacon <will.deacon@arm.com>:
> On Wed, Apr 10, 2013 at 11:04:38AM +0100, Bastian Hecht wrote:
>> We must not declare dbg_cpu_pm_nb as __cpuinitdata as we need it after
>> system initialization for Suspend and CPUIdle.
>>
>> This was done in commit 9a6eb310eaa5336b89a27a0bbb78da4bba35f6f1
>> ARM: hw_breakpoint: Debug powerdown support for self-hosted debug
>>
>> Signed-off-by: Bastian Hecht <hechtb+renesas@gmail.com>
>
> Thanks Bastian, I'll take this into my tree.
>
> Will

Nice, thanks!

[PATCH] ARM: hw_breakpoint: Do not use __cpuinitdata for dbg_cpu_pm_nb

[Dietmar Eggemann]

On 10/04/13 12:26, Bastian Hecht wrote:
> 2013/4/10 Will Deacon <will.deacon@arm.com>:
>> On Wed, Apr 10, 2013 at 11:04:38AM +0100, Bastian Hecht wrote:
>>> We must not declare dbg_cpu_pm_nb as __cpuinitdata as we need it after
>>> system initialization for Suspend and CPUIdle.
>>>
>>> This was done in commit 9a6eb310eaa5336b89a27a0bbb78da4bba35f6f1
>>> ARM: hw_breakpoint: Debug powerdown support for self-hosted debug
>>>
>>> Signed-off-by: Bastian Hecht <hechtb+renesas@gmail.com>
>>
>> Thanks Bastian, I'll take this into my tree.
>>
>> Will
>
> Nice, thanks!
>

Hi Bastian,

thanks for catching this. Is my assumption right that you used an UP kernel?

I didn't catch this error during my Suspend-To-Ram/CPUidle tests because
I tested only on SMP kernels where 'dbg_cpu_pm_nb' is placed into the
.data and not in the .init.data section.


Will, we have the same issue in arch/arm/kernel/perf_event_cpu.c.
Lorenzo is currently working on an appropriate patch.

-- Dietmar

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[PATCH] ARM: hw_breakpoint: Do not use __cpuinitdata for dbg_cpu_pm_nb

[Bastian Hecht]

Hi Dietmar,

2013/4/10 Dietmar Eggemann <dietmar.eggemann@arm.com>:
> On 10/04/13 12:26, Bastian Hecht wrote:
>>
>> 2013/4/10 Will Deacon <will.deacon@arm.com>:
>>>
>>> On Wed, Apr 10, 2013 at 11:04:38AM +0100, Bastian Hecht wrote:
>>>>
>>>> We must not declare dbg_cpu_pm_nb as __cpuinitdata as we need it after
>>>> system initialization for Suspend and CPUIdle.
>>>>
>>>> This was done in commit 9a6eb310eaa5336b89a27a0bbb78da4bba35f6f1
>>>> ARM: hw_breakpoint: Debug powerdown support for self-hosted debug
>>>>
>>>> Signed-off-by: Bastian Hecht <hechtb+renesas@gmail.com>
>>>
>>>
>>> Thanks Bastian, I'll take this into my tree.
>>>
>>> Will
>>
>>
>> Nice, thanks!
>>
>
> Hi Bastian,
>
> thanks for catching this. Is my assumption right that you used an UP kernel?

Yes exactly, it's for a Cortex A9 UP core, so a UP kernel. Glad I could help.

> I didn't catch this error during my Suspend-To-Ram/CPUidle tests because
> I tested only on SMP kernels where 'dbg_cpu_pm_nb' is placed into the
> .data and not in the .init.data section.
>
>
> Will, we have the same issue in arch/arm/kernel/perf_event_cpu.c.
> Lorenzo is currently working on an appropriate patch.
>
> -- Dietmar
>
> -- IMPORTANT NOTICE: The contents of this email and any attachments are
> confidential and may also be privileged. If you are not the intended
> recipient, please notify the sender immediately and do not disclose the
> contents to any other person, use it for any purpose, or store or copy the
> information in any medium.  Thank you.
>

[PATCH] ARM: hw_breakpoint: Do not use __cpuinitdata for dbg_cpu_pm_nb

[Will Deacon]

On Wed, Apr 10, 2013 at 01:11:16PM +0100, Bastian Hecht wrote:
> > Will, we have the same issue in arch/arm/kernel/perf_event_cpu.c.
> > Lorenzo is currently working on an appropriate patch.

I don't think we do. The __cpuinitdata annotation there is only used on a
hotplug notifier, which should be fine.

Will

[PATCH] ARM: hw_breakpoint: Do not use __cpuinitdata for dbg_cpu_pm_nb

[Dietmar Eggemann]

On 10/04/13 13:53, Will Deacon wrote:
> On Wed, Apr 10, 2013 at 01:11:16PM +0100, Bastian Hecht wrote:
>>> Will, we have the same issue in arch/arm/kernel/perf_event_cpu.c.
>>> Lorenzo is currently working on an appropriate patch.
>
> I don't think we do. The __cpuinitdata annotation there is only used on a
> hotplug notifier, which should be fine.

You right, I got confused about what is already upstream.

-- Dietmar

>
> Will
>

-- IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium.  Thank you.