No rotation on Samsung Galaxy S Froyo 2.2.1 : how to restore it

I recently lost the rotation auto on my Galaxy S, and it was not to toggle on the button "rotation auto" in the status bar. Even "calling" the 0 menu to Sensor item did not detected the sensor. So, thanks xda-developers for the solution. The hard part was to foun a way to get root on a 2.2.1 SGS.

The full answer is :

Set the USB debug mode on your phone and connect it to your PC
you’ll have to be root to restore it : the problem is that firmware 2.2.1 check the signature of update.zip files. So I can’t install them with adb. The solution was to install SuperOneClickv1.9.1-ShortFuse (again on xda) to get the phone rooted.It will also install busybox if not found

Then you can run a terminal and call su. Now you can run the last two steps in the shell

the second step is to remove (or rename) the file in /data/system/ms3c_yamaha.cfg
the third is to run /system/bin/sensorcalibutil_yamaha

And Voilà! No reboot. You’ll have the rotation on Google, the compass will work again and you’ll can play your favorites games (eg car race games). And personally, my clock I launch when I go to bed (it’s the way I noticed there was no more auto rotation).