Re: [Xenomai] Linux port to ARM Allwinner A13

[Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>]

On 02/26/2013 01:11 AM, Paul wrote:

> 
> Here is a first port for OLINUXINO A13 board.
> 
> http://www.crubille.lautre.net/xenomai_sun5i/ipipe-linuxsun5i-3.4.24.beta.patch
> 
> and apply the standart xenomai-2.6.2.1 procedure on a sunxi linux kernel 
> from :
> "git clone git://github.com/linux-sunxi/linux-sunxi.git -b sunxi-3.4"


Hi,

good news the I-pipe patch for ARM is ported to yet another board! If
you wish the patch to be distributed with Xenomai, please generate a
-pre and -post patches.

If you generate pre and post patches, we can update the I-pipe patch
with your pre and post patches remaining valid. If you do otherwise,
your patch will bitrot fast.

Since I have been talking about it so many times, I guess we should
provide a script to generate the -pre and -post patches.

> 
> I think that the A10/A13 port in the official linux tree is still too 
> unstable to port on it.
> 
> 
> The patch is a basic but functionnal version. I attempt to use priority 
> interrupt, but go in trouble.
> If i can have comments about this point?


Probably not much more than what you can find in the porting guide.

> 
> If somebody is interested in it for A10, it is very easy to adapt, and i 
> can do it and send the patch.
> 
> Paul Crubillé
> 
> ---------------------------------------------------------------------------------------------------
> 
> Running it, i get
> 
> 
> latency -t 2 -p 100
> == Sampling period: 100 us
> == Test mode: in-kernel timer handler
> == All results in microseconds
> RTT|  00:00:01  (in-kernel timer handler, 100 us period, priority 99)
> RTH|----lat min|----lat avg|----lat max|-overrun|---msw|---lat 
> best|--lat worst
> RTD|      5.583|      6.265|     11.167|       0|     0|      5.583|    
>   11.167
> RTD|      6.125|      6.258|     10.917|       0|     0|      5.583|    
>   11.167
> RTD|      5.500|      6.270|     12.000|       0|     0|      5.500|    
>   12.000
> 
> 
> "lat worst" is mostly under 20 us but can go up for 30 ns.
> 
> latency  -p 100
> == Sampling period: 100 us
> == Test mode: periodic user-mode task
> == All results in microseconds
> warming up...
> RTT|  00:00:01  (periodic user-mode task, 100 us period, priority 99)
> RTH|----lat min|----lat avg|----lat max|-overrun|---msw|---lat 
> best|--lat worst
> RTD|     11.999|     12.708|     21.333|       0|     0|     11.999|    
>   21.333
> RTD|     12.624|     12.791|     21.541|       0|     0|     11.999|    
>   21.541
> RTD|     12.458|     12.791|     26.458|       0|     0|     11.999|    
>   26.458
> 
> "lat worst" is mostly under 40 us but can go up for 80 ns.


Tests done without load are meaningless, try xeno-test or dohell.

-- 
                                                                Gilles.