From: Russ.Dill@ti•com (Russ Dill)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH RFC v1 1/3] ARM: Add irq disabled version of soft_restart.
Date: Tue, 25 Feb 2014 09:15:33 -0800 [thread overview]
Message-ID: <530CCFB5.5030205@ti.com> (raw)
In-Reply-To: <alpine.DEB.2.02.1402251125500.21251@ionos.tec.linutronix.de>
On 02/25/2014 02:27 AM, Thomas Gleixner wrote:
> On Mon, 24 Feb 2014, Russ Dill wrote:
>> On 02/24/2014 03:13 PM, Sebastian Capella wrote:
>>> Quoting Russell King - ARM Linux (2014-02-22 02:26:17)
>>>> On Tue, Feb 18, 2014 at 05:52:07PM -0800, Sebastian Capella
>>>> wrote:
>>>>> From: Russ Dill <Russ.Dill@ti•com>
>>>>>
>>>>> This adds the ability to run soft_restart with
>>>>> local_irq/fiq_disable already called. This is helpful for
>>>>> the hibernation code paths.
>>>>
>>>> I'd rather keep this simple. There's no problem with calling
>>>> soft_restart with interrupts already disabled.
>>>> local_irq_disable()/local_fiq_disable() there should be
>>>> harmless.
>>>
>>> Hi Russell,
>>>
>>> I'm observing a data abort loop when I replace this call:
>>>
>>> In the local_irq_disable, it ends up calling
>>> trace_hardirqs_off (CONFIG_TRACE_IRQFLAGS_SUPPORT is enabled),
>>> which calls trace_hardirqs_off_caller which checks
>>> lockdep_recursion in the current task, but we've switched to a
>>> temporary stack with the call_with_stack, and get_current is
>>> returning NULL. This triggers a data abort, which calls
>>> trace_hardirqs_off again and so on.
>>>
>>> Do you have any suggestions here?
>>>
>>> Thanks,
>>>
>>> Sebastian
>>>
>>
>> So the alternative is to have a version of the call that calls a
>> special no trace version of
>> local_irq_disable()/local_fiq_disable(). Which would be
>> preferable? Having a noirq version of soft_restart seems much
>> simpler to me.
>
> If you want escape the tracer and in that case you really want it
> being on a different stack, use raw_local_irq_* which are not
> traced.
So it might make sense to change soft_restart to use the
raw_local_irq_* calls.
next prev parent reply other threads:[~2014-02-25 17:15 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-02-19 1:52 [PATCH RFC v1 0/3] hibernation support on ARM Sebastian Capella
2014-02-19 1:52 ` [PATCH RFC v1 1/3] ARM: Add irq disabled version of soft_restart Sebastian Capella
2014-02-22 10:26 ` Russell King - ARM Linux
2014-02-24 23:13 ` Sebastian Capella
2014-02-25 0:22 ` Sebastian Capella
2014-02-25 7:56 ` Russ Dill
2014-02-25 10:27 ` Thomas Gleixner
2014-02-25 17:15 ` Russ Dill [this message]
2014-02-25 23:24 ` Sebastian Capella
2014-02-19 1:52 ` [PATCH RFC v1 2/3] Fix hibernation restore hang in freeze_processes Sebastian Capella
2014-02-24 7:09 ` Ming Lei
2014-02-19 1:52 ` [PATCH RFC v1 3/3] ARM hibernation / suspend-to-disk Sebastian Capella
2014-02-19 16:12 ` Lorenzo Pieralisi
2014-02-19 19:10 ` Russ Dill
2014-02-20 10:37 ` Lorenzo Pieralisi
2014-02-19 19:33 ` Sebastian Capella
2014-02-20 16:27 ` Lorenzo Pieralisi
2014-02-21 18:39 ` Sebastian Capella
2014-02-21 23:59 ` Sebastian Capella
2014-02-22 4:37 ` Sebastian Capella
2014-02-22 6:46 ` Russ Dill
2014-02-22 10:22 ` Russell King - ARM Linux
2014-02-22 10:16 ` Russell King - ARM Linux
2014-02-22 12:13 ` Lorenzo Pieralisi
2014-02-22 22:30 ` Pavel Machek
2014-02-21 1:01 ` Sebastian Capella
2014-02-22 10:38 ` Russell King - ARM Linux
2014-02-22 12:09 ` Lorenzo Pieralisi
2014-02-22 22:28 ` Pavel Machek
2014-02-23 19:52 ` Sebastian Capella
2014-02-23 20:02 ` Sebastian Capella
2014-02-25 11:32 ` Lorenzo Pieralisi
2014-02-25 17:55 ` Sebastian Capella
2014-02-26 10:24 ` Lorenzo Pieralisi
2014-02-26 17:50 ` Sebastian Capella
2014-02-26 19:03 ` Lorenzo Pieralisi
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