Debuzzing

Al Johnson openmoko at mazikeen.demon.co.uk
Wed Apr 29 16:19:07 CEST 2009


On Wednesday 29 April 2009, Yorick Moko wrote:
> I know the kernel does that,
> but I normally boot from SD card,
> and when using gps i normally use maps, which are located on the SD card

In my experience the capacitor isn't needed. I don't have it, have both maps 
and rootfs on SD, and don't have problems with GPS. Tests at the time of the 
kernel fix showed the GPS performing to specification even during SD activity.

The second part of the kernel fix was to default the SD drive strength to the 
minimum instead of the higher level it previously used. This has a similar 
electrical effect to the capacitor, but applies to all the SD data lines, not 
just the clock line.

> I think most people will use maps from the sd card and a fair amount
> boots regulary from SD
>
> thanks for taking it into consideration
> y
>
> On Wed, Apr 29, 2009 at 3:44 PM, Dr. H. Nikolaus Schaller
>
> <hns at computer.org> wrote:
> > Am 29.04.2009 um 14:28 schrieb Yorick Moko:
> >> And what about the sd-card??
> >> that is a very easy fix to do
> >> Joerg advised to fix it also
> >
> > It is not really necessary to do that when using a more recent kernel
> > that can switch off the SD card clock:
> > http://wiki.openmoko.org/wiki/GPS_Problems
> >
> > But it does not look very complicated so I will take your suggestion
> > and find out what we can do.
> >
> > Nikolaus





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