Re: [PATCH v2 4/4] Added getsynctime64() callback
From: Richard Cochran
Date: Fri Aug 14 2015 - 02:33:01 EST
On Thu, Aug 13, 2015 at 09:10:36PM +0000, Hall, Christopher S wrote:
> > > + if (!cpu_has_art)
> > > + return -EOPNOTSUPP;
> >
> > Perform this check before registration, setting .getsynctime64
> > accordingly.
>
> The problem here is that ART initialization doesn't happen until we
> install TSC as a clocksource. This design is per Thomas'
> suggestion. That occurs after the driver is loaded (as a module).
So that 'cpu_has_art' actually means 'cpu_has_art_and_has_been_initialized'?
In any case, returning EOPNOTSUPP early on, but OK later seems mean to
me. If the clocks aren't ready yet, the error should be EBUSY so that
user space knows it can try again.
Thanks,
Richard
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/