Problem with i2c-algo-ibm_ocp driver on ppc405 board

Matteo Bortolin matteo.bortolin at
Wed Jan 28 21:24:59 EST 2004

At 10.14 28/01/2004, Wolfgang Denk wrote:

>Dear Matteo,
>in message < at> you wrote:
> >
> > This would mean that a kernel that use  i2c-algo-ibm_ocp.c and a i2c
> > RTC-driver cannot work properly
> >
> > Is this correct?
>This is correct.  This  is  exactly  the  reason  why  we  added  the
>CONFIG_RTC_11_MINUTE_MODE config option in our kernel tree - with the
>official kernels you will ALWAYS crash, as there is no such option.
> > If yes, how can I solve my problem?
>Do not enable CONFIG_RTC_11_MINUTE_MODE?
>Do you understand what 11 minute  mode  means?  And  do  you  really,
>really  want  such  a  behaviour?  In  almost all cases I've seen the
>accuracy of the external RTC was much better than that of the  system
>clock.  In  such  a case you may either just set the system time from
>the RTC at boot time (and then let  the  system  time  drift  out  of
>sync),  or  run NTPD to keep the system time synced with the RTC (the
>RTC being the normal). I have been told that there are  installations
>where  the  11 minute mode is being used (and believed to be useful),
>but I don't know any. Especially not in embedded systems.
>Best regards,
>Wolfgang Denk
>See us @ Embedded World, Nuremberg, Feb 17 - 19,  Hall 12.0 Booth 440
>Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd at
>The light at the end of the tunnel is usually a "No Exit" sign.

thank you very much for your help!

Matteo Bortolin


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