Re: [PATCH 0/3] capebus moving omap_devices to mach-omap2

[Grant Likely]

On Mon, Nov 5, 2012 at 7:54 PM, Pantelis Antoniou
<panto@xxxxxxxxxxxxxxxxxxxxxxx> wrote:
>> This handles many of the use cases, but it assumes that an overlay is
>> board specific. If it ever is required to support multiple base boards
>> with a single overlay file then there is a problem. The .dtb overlays
>> generated in this manor cannot handle different phandles or nodes that
>> are in a different place. On the other hand, the overlay source files
>> should have no problem being compiled for multiple targets, so maybe
>> it isn't an issue. Plus if dtc is installed on the target, then the
>> live tree from /proc can be used as the reference when compiling the
>> overlay.
>
> My worry is that this format is dependent on linking against the board
> DTS file. One of the ideas thrown around here was that it might make
> sense to store the DTB fragment in the EEPROM of the device.

Right, that wouldn't work well if the base DT changed, or if a
BeagleBone2 is released that has the same header configuration, but
different backing devices. It would be nice to have a solution for
that.

> In that case you have a OS independent hardware description, which can
> be even used even by the bootloader to access devices it knows not about
> at compile time.
>
> Other than that, I have no other objections.

I'm open to suggestions if anyone has any. I have not objections to a
fixup approach, but I'm not comfortable with anything that is fragile
to modifications to the fragment.

g.
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