GPS rework: Please test and report on software fix prior to attempting any hardware fix

[Al Johnson]

On Wednesday 06 August 2008, Andy Green wrote:
> | d i   min /  avg / max
> | 0 0  35.20/ 55.33/144.30   <===
> | 0 1  37.39/ 77.76/315.76
> |
> | 3 0  36.07/ 42.07/ 47.82   <===
> | 3 1  97.46/173.09/359.69
>
> These relative numbers are a bit counterintuitive... it might be worth
> trying it again from a "very cold boot" but with the script

From experience writing the script I think they look within the normal range 
of variation for a FR sitting near a window, and that if you increased PASSES 
the stats for all of the IDLECLK=0  runs would look the same if the card 
wasn't being exercised. I got to see a lot of such apparently 
counterintuitive results before I forced access to the card after writing the 
sysfs entries! From the same location some runs have a best ttff of ~150s 
while others are consistent at around 35-40s. Some start with good ttff, go 
through a period of poor ttff then back to good again. This would be more 
visible if people posted the raw results rather than the statistics.

I suspect from a couple of observations that a GSM register may make ttff 
longer, but I don't have any data to back that up - it may just have been 
unlucky. Any ideas on how GSM status could be factored in?

I suppose I should post some results too. Note the 2 results where there seems 
to have been a GPRMC result sitting in a serial buffer or something.
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d i time
0 0 real 2m 20.77s
0 1 real 6m 5.84s
1 0 real 2m 7.67s
1 1 real 3m 6.97s
2 0 real 1m 19.33s
2 1 real 9m 59.40s
3 0 real 0m 49.44s
3 1 real 1h 15m 34s
0 0 real 2m 6.22s
0 1 real 6m 25.13s
1 0 real 0m 58.47s
1 1 real 4m 45.95s
2 0 real 2m 10.15s
2 1 real 5m 55.50s
3 0 real 1m 24.57s
3 1 real 54m 27.04s
0 0 real 2m 14.25s
0 1 real 5m 49.14s
1 0 real 0m 40.93s
1 1 real 4m 54.68s
2 0 real 0m 55.83s
2 1 real 5m 39.02s
3 0 real 0m 39.20s
3 1 real 7m 32.77s
0 0 real 0m 46.20s
0 1 real 3m 6.79s
1 0 real 0m 38.62s
1 1 real 1m 20.72s
2 0 real 0m 48.52s
2 1 real 4m 4.87s
3 0 real 1m 3.03s
3 1 real 5m 56.27s
0 0 real 0m 53.03s
0 1 real 2m 8.48s
1 0 real 2m 40.71s
1 1 real 1m 57.13s
2 0 real 2m 1.89s
2 1 real 2m 59.68s
3 0 real 0m 57.95s
3 1 real 4m 41.03s
0 0 real 0m 42.63s
0 1 real 2m 10.56s
1 0 real 0m 46.22s
1 1 real 0m 0.14s
2 0 real 0m 48.24s
2 1 real 5m 40.03s
3 0 real 0m 56.11s
3 1 real 9m 16.78s
0 0 real 0m 38.74s
0 1 real 1m 3.09s
1 0 real 0m 49.23s
1 1 real 0m 0.14s
2 0 real 0m 48.09s
2 1 real 2m 47.54s
3 0 real 0m 53.33s
3 1 real 9m 18.26s
0 0 real 0m 40.45s
0 1 real 2m 10.75s
1 0 real 0m 46.27s
1 1 real 3m 10.67s
2 0 real 0m 48.13s
2 1 real 3m 24.71s
3 0 real 0m 37.41s
3 1 real 10m 9.89s
0 0 real 0m 39.93s
0 1 real 1m 9.94s
1 0 real 0m 39.97s
1 1 real 2m 2.57s
2 0 real 0m 47.56s
2 1 real 3m 36.03s
3 0 real 0m 43.44s
3 1 real 6m 16.24s
0 0 real 2m 1.56s
0 1 real 3m 13.48s
1 0 real 0m 40.60s
1 1 real 2m 37.83s
2 0 real 0m 39.71s
2 1 real 2m 31.22s
3 0 real 0m 51.98s
3 1 real 6m 3.22s