On Sat, 15 Nov 2008 18:37:56 +0000 Andy Green <[EMAIL PROTECTED]> wrote:
> | I don't know it if this could be usefull but there's been a > | submission of an accelerometer driver (ST LIS3LV02Dx) for mainline > | inclusion, see > [1]. > > | [1] - http://lkml.org/lkml/2008/10/18/144 > > Thanks for the tip... I guess this explains why that driver doesn't > have the difficulty around SPI IO in interrupt context... Yep, good find! > ''* Andrew Morton asked to investigate using interrupt-based sensor > reading (instead of timer-based): it turns out not useful because the > sensor generate interrupts even if the data has not changed, so we end > up waking up at 40Hz'' > > I think it is useful alright to have a reliably constant period > between samples, it just makes trouble for IO subsystem that can't > operate in interrupt context; the threshold stuff can help with the > absolute amount of samples. Well, for the threshold stuff the driver needs to be interrupt driven. It's good to see another driver, but I don't think it would be useful for openmoko - it uses a kernel thread that wakes up every 50 ms and reports data. That would not be good for battery life :-) // Simon
