PATCH/RFC [0/3]: Fix suspend and other acceleromter issues

Sean McNeil sean at
Sun Nov 16 06:59:16 CET 2008

Andy Green wrote:
> Hash: SHA1
> Somebody in the thread at some point said:
> |> For the accelerometers, the problem boils down to the FIFO not being
> What FIFO?  Where?  There's no FIFO in the accels.

I'm sure you know the hardware better than I, but behavior indicates 
there is either some sort of internal FIFO or a buffer of some kind. 
There is a bit that tells you when a sample is ready to read. That bit 
can generate an interrupt. The old code would then read one sample on an 
edge interrupt and return. The problem was that the bit could at times 
not get reset because of delays and there are actually 2 samples to 
read. We can solve by either making level trigger or looping until the 
bit is cleared. I prefer level trigger because if it breaks we get an 
interrupt storm but the phone still functions. Looping in an interrupt 
can be hard to debug.

> - -Andy
> Version: GnuPG v1.4.9 (GNU/Linux)
> Comment: Using GnuPG with Fedora -
> iEYEARECAAYFAkkevK8ACgkQOjLpvpq7dMpM+wCfYnM4tsQFK8pvgClET2SFFjHp
> VG0AnjcKEe1pU5tLuHweEV0K7SaBUK58
> =Fa39

More information about the openmoko-kernel mailing list