[PATCH v4 1/3] Runtime Interpreted Power Sequences
Alex Courbot
acourbot at nvidia.com
Fri Aug 24 19:24:54 EST 2012
On Tuesday 21 August 2012 17:54:20 Tomi Valkeinen wrote:
> > However this also means we'll essentially just be moving the board code.
>
>
> What do you mean "just"? Wasn't the point of the whole "arm board file
> mess" to get rid of the code from the board files? If the code in the
> board file is device specific code, not board specific, then the driver
> of the device is a logical place to place it.
I think Tomi has a point here - these sequences were not belonging to the
board code in the first place. They are definitely tied to the device, hence
should have been handled by the driver all along, with the board code
assigning the correct resources to the device (like the vast majority of
device drivers do).
> And as I said, I don't have any problems with some kind of generic power
> sequences. So the code in the board file could be moved and converted to
> use the power sequences, if that is better than just plain c code.
My concern now is, provided that all drivers to their job and handle how their
devices are switched on and off, when (if at all) are encoded power sequences
better than their equivalent C code? There is the matching database size issue
that you mentionned, is it a sufficient concern to justify a new kernel feature?
On the other hand some devices like panels are typically not used in many
different appliances, so maybe it is not worth to separate them from their
board definition. As Mark mentionned, having .dtsi files for the DT (and their
equivalent .h for kernels that use platform data) might be a good middle
ground.
But the line is really tight between what is code and what is data here.
Alex.
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