[ECOS] ARM FIQ handling problem

[ECOS] ARM FIQ handling problem

[Rupesh Kumar]

Hi All,

I am facing some problem with ARM-FIQ handling.

I have two interrupts when i keep one of them as FIQ and Other as IRQ
then i am getting exceptions(Data Abort,Undefined Instructions..)
When both are IRQ then everything is fine.

This i am expecting to be problem with eCos FIQ Handling.

I have seen the mailing list and found out that my problem is similer
to this thread I have tried the approaches in this thread but they are
not helping me.

http://sourceware.org/ml/ecos-devel/2004-10/msg00083.html

Can any one please help me.

Thanks
Rupesh

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[ECOS] Re: ARM FIQ handling problem

[Sergei Organov]

"Rupesh Kumar" <a.rupesh.k@gmail.com> writes:
> Hi All,
>
> I am facing some problem with ARM-FIQ handling.
>
> I have two interrupts when i keep one of them as FIQ and Other as IRQ
> then i am getting exceptions(Data Abort,Undefined Instructions..)
> When both are IRQ then everything is fine.
>
> This i am expecting to be problem with eCos FIQ Handling.

What version of eCos do you use? Latest version from CVS should have
some fixes for ARM HAL including a fix for FIQ handling. In particular,
refer to this one:

<http://sourceware.org/ml/ecos-patches/2006-02/msg00001.html>

-- 
Sergei.

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[ECOS] Re: ARM FIQ handling problem

[R&D4]

Hi Rupesh!

apart some other minor changes (for FIQ vs IRQ configuration) I just use
two differt stack for IRQ and FIQ handling, much like Gary pointed out
in this topic:

http://sourceware.org/ml/ecos-devel/2004-10/msg00087.html

If I recall correctly you should also change a bit of code in FIQ
handling inside vectors.S, because there is a fall through to IEQ code
that MUST be avoided (so just duplicate the code! :-) )

Take care to disable FIQ and not only IRQ when handling FIQ, of course.

After those changed I had 1 FIQ and many IRQ working together preatty
well (with a good impact on interrupt latency! :-) )

HTH

Best Regards,


-- 

Amon

DAVE Srl - Electronics System House
e-mail address: r&d4@dave-tech.it


Rupesh Kumar wrote:
> Hi All,
> 
> I am facing some problem with ARM-FIQ handling.
> 
> I have two interrupts when i keep one of them as FIQ and Other as IRQ
> then i am getting exceptions(Data Abort,Undefined Instructions..)
> When both are IRQ then everything is fine.
> 
> This i am expecting to be problem with eCos FIQ Handling.
> 
> I have seen the mailing list and found out that my problem is similer
> to this thread I have tried the approaches in this thread but they are
> not helping me.
> 
> http://sourceware.org/ml/ecos-devel/2004-10/msg00083.html
> 
> Can any one please help me.
> 
> Thanks
> Rupesh
> 
> 

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[ECOS] Re: ARM FIQ handling problem

[Rupesh Kumar]

> What version of eCos do you use? Latest version from CVS should have
> some fixes for ARM HAL including a fix for FIQ handling. In particular,
> refer to this one:
>
> <http://sourceware.org/ml/ecos-patches/2006-02/msg00001.html>

Thanks Sergei.
This one solved my issue.

I used the CVS Version and it is working .

But when we are entering the irq mode we are disabling the fiq.
so when we are in the IRQ Handler we cant get FIQ.Correct me if i am wrong.

What i want is even if i am busy in the Interrupt Handler i should get
FIQ.Can this be possible.

Regards
Rupesh

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[ECOS] Re: ARM FIQ handling problem

[Sergei Organov]

"Rupesh Kumar" <a.rupesh.k@gmail.com> writes:

>> What version of eCos do you use? Latest version from CVS should have
>> some fixes for ARM HAL including a fix for FIQ handling. In particular,
>> refer to this one:
>>
>> <http://sourceware.org/ml/ecos-patches/2006-02/msg00001.html>
>
> Thanks Sergei.
> This one solved my issue.
>
> I used the CVS Version and it is working .
>
> But when we are entering the irq mode we are disabling the fiq.
> so when we are in the IRQ Handler we cant get FIQ.Correct me if i am wrong.
>
> What i want is even if i am busy in the Interrupt Handler i should get
> FIQ.Can this be possible.

Yes, I think it's possible, but it requires substantial changes to the
ARM HAL. [And to tell the truth I think ARM HAL cries for re-design
anyway as current design goes against ARM architecture in every aspect
of interrupts/exception handling I can think of and instead emphasizes
its disadvantages.]

-- 
Sergei.


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