[Xenomai] powerpc 440 userspace latency test does nothing

Seeger, Steven D. (GSFC-444.0)[Embedded Flight Systems, Inc] steven.seeger at nasa.gov
Sun Dec 6 19:20:42 CET 2015


Thanks for the suggestion. I will look at the interrupt controller and then get back to you.
I will have access to the board again on Friday.

It does sound like we should be able to get decent numbers with this board.
________________________________________
From: Philippe Gerum [rpm at xenomai.org]
Sent: Sunday, December 06, 2015 10:43 AM
To: Seeger, Steven D. (GSFC-444.0)[Embedded Flight Systems, Inc]; xenomai at xenomai.org
Subject: Re: [Xenomai] powerpc 440 userspace latency test does nothing

On 12/06/2015 04:46 AM, Steven Seeger wrote:
> I went ahead and used the ipipe-core-3.14.39-powerpc-8 patch and built the
> vendor's 3.14.2 kernel against it. I didn't have to do as much work as I did
> with the 3.18.20 patch. I had the same results (both with latency and with
> freezing.)
>
> At this point I've got the answers I need from this exercise, but it would be
> good to understand the problem and possibly fix it. If anyone can point me in
> the right direction maybe I can take a look at it.
>

For the Virtex5 family, we likely need the xilinx-intc controller, and
that one has not been made pipeline-aware in the kernel tree. I checked
Xenomai 3.0.1 over a yosemite 44xFP SoC and all went well, so this is
consistent with a SoC-dependent issue on the ml507 (AMCC's 440EP sports
a single UIC).

I would suggest to have a look at arch/powerpc/sysdev/xilinx_intc.c, and
make sure it implements the I-pipe helpers and tweaks.

/proc/interrupts should reveal all interrupt controllers in use for a
given configuration (make sure to enable GPIOs to have a complete
report). From that point you should be able to cross-check that each of
them is supported by the pipeline.

--
Philippe.



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