Re: [Xenomai] Porting Xenomai on Odroid-U3

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

On Mon, Jan 26, 2015 at 08:52:19PM +0100, Arnaud Degroote wrote:
> On 26/Jan - 20:09, Gilles Chanteperdrix wrote:
> > On Mon, Jan 26, 2015 at 08:02:41PM +0100, Arnaud Degroote wrote:
> > > Hi list,
> > > 
> > > I'm trying to port Xenomai on Odroid-U3. I read on the list that there
> > > is a first try by GP Orcullo, so I start from its work.
> > > 
> > > I'm working on a 3.17.8 kernel on which I ported the Ipipe / Xenomai
> > > patch. I validated it on two omaps platform where I don't see regression
> > > against previous version of the patch, so I'm fairly confident that the
> > > core part is correct. In a second time, I ported the previous effort of
> > > GP Orcullo. The current state of the effort is available on 
> > > 
> > > https://github.com/adegroote/linux/tree/linux-stable-xenomai-odroid-3.17.y
> > > 
> > > I tested without IPIPE, and with IPIPE. Troubles start with the XENOMAI
> > > option. Basically, the kernel seems to hangs when I load any "skin" (I
> > > compiled them in modules to be sure). For example, 
> > > 
> > > modprobe xeno-native
> > > 
> > > prints
> > > 
> > > Xenomai: starting native API services.	
> > > 
> > > but I cannot get back the shell prompt.
> > > 
> > > From the Troubleshooting part, I suppose something is wrong with the
> > > ipipe_timer, but I don't have much idea where to look for. 
> > > 
> > > Can someone give me some inputs about how to trace / debug this issue
> > > or/and quickly check if I miss something obvious in my patch.
> > > 
> > > https://github.com/adegroote/linux/commit/81c6ebeb3127efdceb3e31f9d3f1f400ecbb579f.patch
> > 
> > Well, you should put some printks in the timer code to see what is
> > the last action done. Is the ->ack function called, does it really
> > acknowledge the timer interrupt at timer level (because if it does
> > not, the interrupt will trigger again at the end of the current
> > interrupt).
> 
> Thanks Gilles,
> I will try tomorrow morning, when I will be back to work.
> > 
> > Could you post a link to the patched file handling the timer ?
> 
> The timer used is exynos-mct, available here
> 
> https://github.com/adegroote/linux/blob/linux-stable-xenomai-odroid-3.17.y/drivers/clocksource/exynos_mct.c

The ISR is wrong. The acknowledge should be skipped when the timer is
stolen, not the event handler.

-- 
					    Gilles.