From mboxrd@z Thu Jan  1 00:00:00 1970
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Date: Wed, 03 Jun 2009 15:11:05 +0200
From: Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>
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Subject: Re: [Xenomai-core] [PATCH 2/3] RTDM: Instrument rtdm_lock_get for
 proper use
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To: Jan Kiszka <jan.kiszka@domain.hid>
Cc: xenomai@xenomai.org

Jan Kiszka wrote:
> Gilles Chanteperdrix wrote:
>> Jan Kiszka wrote:
>>> In case the user thinks rtdm_lock_get could be used like spin_lock or
>>> messes up the IRQ protection for other reasons, catch this with a
>>> XENO_BUGON.
>>>
>>> Signed-off-by: Jan Kiszka <jan.kiszka@domain.hid>
>>> ---
>>>
>>>  include/rtdm/rtdm_driver.h |    8 ++++++++
>>>  1 files changed, 8 insertions(+), 0 deletions(-)
>>>
>>> diff --git a/include/rtdm/rtdm_driver.h b/include/rtdm/rtdm_driver.h
>>> index 058a9f8..fe42eea 100644
>>> --- a/include/rtdm/rtdm_driver.h
>>> +++ b/include/rtdm/rtdm_driver.h
>>> @@ -655,7 +655,15 @@ typedef unsigned long rtdm_lockctx_t;
>>>   *
>>>   * Rescheduling: never.
>>>   */
>>> +#ifdef DOXYGEN_CPP /* Beautify doxygen output */
>>>  #define rtdm_lock_get(lock)	rthal_spin_lock(lock)
>>> +#else /* This is how it really works */
>>> +#define rtdm_lock_get(lock)					\
>>> +	do {							\
>>> +		XENO_BUGON(RTDM, rthal_local_irq_test());	\
>>> +		rthal_spin_lock(lock);				\
>>> +	} while (0)
>>> +#endif
>> Why is it a problem to call rthal_spin_lock with irqs off?
> 
> Did I messed it up again? I meant it is a problem to call it with irqs
> *on*. Checking what rthal_local_irq_test() actually means... Hmm, I
> still think it's correct. Maybe we should rename rthal_local_irq_test to
> rthal_local_irq_enabled to clarify the usage.

Ok. Got it. So, maybe, what you want is:

if (rthal_local_irq_test())
	xnpod_lock_sched();
rthal_spin_lock

?

-- 
					    Gilles.