Re: [PATCH v4 2/2] iio: light: ROHM BH1745 colour sensor

[Jonathan Cameron <jic23@kernel.org>]

> > Gut feeling is normally people are actually cranking scaling of light
> > channels up and down together as hopefully they are approximately balanced
> > for 'white' giving similar scales on all sensors (by filters or fixed gains)  
> 
> I appreciate your insight on how people usually use these devices :) 
> It's very valuable to me.

Pah, never trust me on this stuff.  I've not been on the 'ground' with
real sensor for a long time and even then my use cases were far from typical.

These days I just play with big toys (though having just helped moved them
between buildings this week I can say that they are at least real and not all
in the cloud).

> 
> > and people would only need to care if they were trying to measure a weak
> > blue signal in a red world. If we have a case that doesn't work well
> > for that sort of global scaling (I can sort of see that as a possible
> > problem due to the transition states not being possible) then we
> > should make sure that one works!  
> 
> Yes. I think some users will eventually hit to a scale transition which 
> will be NACKed by the driver. Also, I don't think this problem will be 
> specific to the BU27034 sensor, but in some form this will be possible 
> for many gain-time-scale type devices. I just don't have a good generic 
> solution in my mind right now.
> 
> Oh, besides, it seems raining stopped. Time to turn off my computer and 
> go out to the yard :)

Wise!


> 
> Yours,
> 	-- Matti
>