Re: [Adeos-main] Ipipe hangs on ARM MINI2440 after switching clocksource

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

Alexey Galakhov wrote:
>> There was a bug some time ago, which was fixed for TIMER3, see commit:
>>
>> http://git.xenomai.org/?p=ipipe-gch.git;a=commit;h=ebf2fac4298e25509ba47942b9fad408dcefce1e
>>
> 
> Oh, I know about this bug. That's the first thing I checked. I found that it
> is already fixed in my case. However, it is still unclear for me where the
> correct MUXes for timer4 and timer3 are initialized, seems to be kind of
> magic. I didn't checked TCFGs against the datasheet, going to do it now. I
> also think about making the free-running timer selectable from config since
> some machines may have something wired to timer3's PWM.
> 
> I forgot to say, it works with patched kernel if CONFIG_IPIPE=no. Timers are
> the same in both cases. I don't quite understand, however, how the
> non-working free-running timer may affect the system in that case.
> Interrupts from timer4 are still generated, so the system may boot with
> ipipe off even with broken free-running timer without any obvious problems,
> am I right?
> 
> 
>> But I think your problem has more to do with the following commit, could
>> you try reverting it?
>>
>> http://git.xenomai.org/?p=ipipe-gch.git;a=commitdiff;h=6ab29d9c7a4b119f45ef4d93780e894fe1c0c6c6;hp=cd9c5e016092258d4450e137be2d0844d0fe8b38
>>
>> The same issue was reported on ixp4xx.
>>
> 
> I'll give it a try tomorrow, thanks. A little question about this part of
> the patch:
> -       if (!__ipipe_mach_timerstolen)
> +       if (!__ipipe_mach_timerstolen) {
> +               spin_lock(&timer_lock);
>                 getticksoffset_tscupdate();
> +               spin_unlock(&timer_lock);
> +       }
> Is it a bugfix (forgotten spinlock added) or is it due to change of
> getticksoffset_tscupdate() contents? (Just trying to understand how it
> works.)

Looks like a mistake... Not having an S3C platform, I modified this code
and only compile-tested it.

-- 
                                                                Gilles.