Re: [PATCH v2 6/7] iio: inv_mpu6050: Reformat sample for active scan mask

From: Crestez Dan Leonard
Date: Mon May 30 2016 - 09:45:10 EST

On 05/29/2016 06:47 PM, Jonathan Cameron wrote:
> On 18/05/16 16:00, Crestez Dan Leonard wrote:
>> Right now it is possible to only enable some of the x/y/z channels, for
>> example you can enable accel_z without x or y but if you actually do
>> that what you get is actually only the x channel.
>> Fix this by reformatting the hardware sample to only include the
>> requested channels.
> As it stands here there is no benefit in doing this over using the core
> demux. In fact it's considerably less efficient (fair enough that you
> are keeping it simple in the first instance).
> The patch description should make that clear.

Why is it less efficient? All it really does is a bunch of memcpy.

> I'd definitely like to see simple extension of that option to handle
> a callback to get the nearest scanmask that is possible (as an alternative
> to the static scan_masks_available list.)
> This only gets interesting if we are dealing with the unaligned case and for
> these parts that only kicks in I think if the slave devices have say 3 bytes in
> their data type.

But I want to deal with the unaligned case because it's better than
introducing odd validations on slave channels. If I added an extension
to get the nearest scanmask I would have to remove it in PATCH 7.