Re: [Xenomai-help] irqloop hangs on Beagleboard ARM with 2.5.5.2/2.6.33

[Wolfgang Grandegger <wg@domain.hid>]

On 03/07/2011 10:27 PM, Gilles Chanteperdrix wrote:
> Eric Eric wrote:
>> On Mon, Mar 7, 2011 at 2:07 PM, Gilles Chanteperdrix
>> <gilles.chanteperdrix@xenomai.org> wrote:
>>> Eric Eric wrote:
>>>> OK, it looks like I would basically have to replace gpioirq-hw.h
>>>> bare-bones GPIO driver for the beagle to get this to work.  Other than
>>>> that, am I correct that the hardware configuration would be two boards
>>>> connected to each other using two GPIO pins for trigger and response?
>>> Well, the gpiolib functions are safe to be used from real-time domain.
>>
>> Hmm, it looked like gpioirqbench went through some pain to -not- use
>> gpiolib and to manually configure and operate the hardware, so I
>> assumed this was not safe.  It's certainly a more pleasant task using
>> gpiolib.  It does beg the question why gpioirqbench isn't doing this.
> 
> The reason is historical.

Right, at that time only a few archs/systems supported the gpolib,
especially with interrupts. But I already have an implementation for the
Qong i.MX31 board using the generic gpiolib. I will dig for it later
this week. "gpioirqbench" measures how fast iPipe or Xenomai software
can respond to an external event (interrupt) in a user-space or
kernel-space task or the Xenomai or iPipe interrupt handler. Anyway,
"gpioirqbench" also needs a host to trigger and measure the latencies in
*hardware*. This is the tricky part. I used a mpc8xx based system.

Wolfgang.