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Date: Tue, 17 Jan 2012 20:27:52 +0100
From: Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>
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Subject: Re: [Xenomai-help] Xenomai IRQ question
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To: Terry Fryar <terry.fryar@domain.hid>
Cc: xenomai@xenomai.org

On 01/17/2012 05:25 PM, Terry Fryar wrote:
> Ok, on a falling edge irq, I'm using an RTDM driver and I'm down to 2.3uS,
> which is quite an improvement.  However, it's still not fast enough...I need
> to hit a window of about 500nS.  Any other suggestions?

>>From what I recall, irq latency under load on a 720 MHz OMAP3 is more
around 20us.

> 
> I use the rtdm_irq_request to hook the ISR, and I set up the irq by hand
> using mem mapping to directly access the registers on the beagle.  At this
> point, I'm not sure where else to try and speed things up?

500ns is not much. I do not think we support this kind of latency on any
processor.

-- 
                                                                Gilles.