On Tue, 22 Jul 2003, Wolfgang Denk wrote:
> > I share your dislike of updating the RTC for performance reasons; these
>
> There are more problems with the 11 minute mode. We ran into this
> issue for hard on some PowerPC systems. Assume a situation where the
> RTC is connected through a I2C bus. Problem 1: normally the i2c
> drivers will be loaded prety late, which means the system will run
> initially with an undefined time. Problem 2: on some actions a i2c
> transfer involves programming an on-chip i2c controller, which will
> perform the task and then signal it's done by an interrupt. On such a
> system the 11 minute mode will crash the system because rtc_set will
> be called from interrupt contect itself.
>
> There was a somewhat controverse discussion on the linuxppc_dev
> mailing list, without a real solution.
A possible solution is to make the update configurable with a sysctl. It
really begs for it. I think it may be worth discussing at the LKML.
Additionally Ulrich Windl may wish to share a few thoughts on the matter.
--
+ Maciej W. Rozycki, Technical University of Gdansk, Poland +
+--------------------------------------------------------------+
+ e-mail: macro@ds2.pg.gda.pl, PGP key available +
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