[PATCH] Don't disable irqs in set_next_event and set_mode callbacks

Remy Bohmer linux at bohmer.net
Wed Sep 23 17:04:09 EDT 2009


2009/9/21 Uwe Kleine-König <u.kleine-koenig at pengutronix.de>:
> These functions are called with irqs already off.
> at91rm2000 had a WARN_ON_ONCE if irqs were enabled since Nov 2008 with
> noone reporting having hit it.

I guess this is not a processor widely used these days with recent
kernels, it has been deprecated by Atmel a couple of years ago.
Besides that, there is also a TC-library clocksource/event
implementation inside the kernel that runs at a much higher frequency
compared to the 32kHz the PIT is running on. It is likely that someone
who cares about accurate timestamps would use the TC-lib
implementation on this processor. So, it would have surprised me if
anybody would actually hit this WARN_ON_ONCE...

> It should be safe to remove now.

But anyway, if the problem we encountered back then would still be
here, many more boards/architectures would suffer from the same
problem. So, I guess it is safe to remove the irq_disable now.
But to be completely sure; I will test this patch on 2.6.31-rt11 with
the sam9261 processor once I have it running stable.(I expect Friday
and stress it during the weekend. Will inform you about the results on

> should I split the patch?  Would you prefer to add a WARN_ON_ONCE for
> some time (as at91rm9200 had it)?

I expect this is not needed...

Kind Regards,


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