lkml.org 
[lkml]   [2014]   [Feb]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH RFC v1 1/3] ARM: Add irq disabled version of soft_restart.
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.


\
 
 \ /
  Last update: 2014-02-25 10:01    [W:0.071 / U:0.128 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site