date and GPS related questions

Rask Ingemann Lambertsen rask at
Sat Mar 14 15:32:23 CET 2009

On Thu, Mar 12, 2009 at 10:19:05PM +0100, Fernando Martins wrote:
> Hi,
> 1) I got the date reset to 1970 a few times. I was not paying attention 
> but I guess this happens when battery is removed, i.e., there's no 
> battery specific for the clock?

   There was a kernel bug that would cause failure to read the hardware
clock on the following dates:
March 1st, 2nd and 3rd.
May, July, October, December 1st.

   Additionally, if the device was off or suspended across the beginning of
a month, you might have seen it lose or gain a day. Behaviour during January
was undefined. All of this because the hardware clock was one month behind:

   I don't which distributions ship a kernel with this bug fixed. I'm also
still looking for someone with a GTA01 to confirm that the bug also exists
with the pcf50606-rtc driver as well.

> 2) Several posts mentioned that GPS could only get the fix if date was 
> correct, the requirements being within 1 sec precision.

   That's only when feeding the GPS with data to speed up getting a fix.
Unassisted GPS works fine with incorrect date and time.

Rask Ingemann Lambertsen
Danish law requires addresses in e-mail to be logged and stored for a year

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