Re: [Xenomai-core] Xenomai on Xscale (Linux 2.6.20)

[Jan Kiszka <jan.kiszka@domain.hid>]

ROSSIER Daniel wrote:
> Hi everyone,
> 
> I'm taking over the original thread from Patrick concerning the port of
> Xenomai on Xscale with Linux 2.6.20. Briefly summarized, the boot
> process actually freezes after a while right after the nucleus has been
> started.
> 
> I've investigated the issue over the last hours, and I came up with the
> following conclusion: it seems that the problem is due to a endless loop
> in do_gettimeofday in arch/arm/kernel/time.c. Here is the code:
> 
> "...
> do {
> 		seq = read_seqbegin_irqsave(&xtime_lock, flags);
> 		usec = system_timer->offset();
> 		sec = xtime.tv_sec;
> 		usec += xtime.tv_nsec / 1000;
> 	} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
> ..."
> 
> If I remove the do { } while loop with the call to
> read_seqbegin_irqsave(), then the boot process is going ahead (I got a
> suspicious error like "I-pipe: Detected illicit call from domain
> 'Xenomai' " but it might well be normal with such a modification.

Please post the full oops about that "illicit call". It may point to an
otherwise hidden invalid usage of Linux services over the Xenomai domain
and explain the lock-up.

Jan

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