[RFC PATCH] Fix accelerometer resume path

Michael Trimarchi trimarchi at gandalf.sssup.it
Mon Oct 12 19:29:28 CEST 2009

Werner Almesberger wrote:
> Michael Trimarchi wrote:
>> This fix the resume path of the accelerometer. If the accelerometer
>> is not power up, restore to initial status.
> That code looks indeed very fishy.
> However, it makes me wonder why the copy is being changed in the first
> place. It doesn't look like the sort of thing you do without a reason,
> good or bad.
> Also, the LIS302 manual is very terse on the semantics of the "power
> down mode". If there are operations that aren't permitted in power
> down mode, it may well be necessary to keep the chip in power up while
> restoring the registers. This could be accomplished by putting
> LIS302DL_REG_CTRL1 last in regs_to_save.
> If all power down does is stop collecting data, then your patch would
> be correct as is.
Ok, we must check on the datasheet this issue. Experience on the device
show me that the patch is correct so it is possible to write on it.

Another solution can be a reverse restore so the CTRL1 is the last one


> - Werner

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