Re: The state of Xenomai 4 on Xilinx Zynq-7000 (or ARM32 in general)

On 17.08.26 14:05, Gerte Hoogewerf wrote:
> Hey Jan/Philippe,
> 
> Thanks for pointing me in this direction.  I've done a bit of research
> and I'm making good progress.
> 
> It actually booted as soon as I disabled the "scutimer" clock source
> via the DTB.  This made the kernel fall back to "arm_global_timer" and
> now it boots properly.
> 
> So, the original problem may be in Dovetail's "smp_twd" handoff under SMP.
> 

Was that actively used with 5.4-ipipe or older? Not that it wasn't and
just happened to be pulled in by Linux > 5.4.

>> [..] if someone is willing to set up a lava working with a Zynq board [..].
>> Still, it would also need someone to look into regressions, just like now...
> 
> I'm unaware of lava. Aside from Xenomai's patches, our boards need a
> massive patchset to function fully (NAND flash, FPGA, etc.).  So, our
> board is not the best testing vehicle. However, I am happy to help
> test periodically, that's a small favor to return.
> 

That would indeed be welcome already.

> Let me know if you have any thoughts on where to look in smp_twd.c;
> otherwise I'll keep digging on my end and report back.
> 

Looking at smp_twd.c in 5.4-ipipe and 5.10-dovetail as well as
6.18-dovetail, the major differences are around

"Updates clockevent frequency when the cpu frequency changes.
 Called on the cpu that is changing frequency with interrupts disabled."

But that path is only taken if CONFIG_COMMON_CLK is not set for the
target - it should be ARCH_ZYNQ.

Jan

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