Re: [PATCH 0/2] of: change overlay apply input data from EDT to FDT

From: Frank Rowand
Date: Mon Jan 29 2018 - 19:23:04 EST


On 01/29/18 06:08, Geert Uytterhoeven wrote:
> Hi Frank,
>
> On Mon, Jan 29, 2018 at 3:53 AM, <frowand.list@xxxxxxxxx> wrote:
>> From: Frank Rowand <frank.rowand@xxxxxxxx>
>>
>> Move duplicating and unflattening of an overlay flattened devicetree
>> (FDT) into the overlay application code. To accomplish this,
>> of_overlay_apply() is replaced by of_overlay_fdt_apply().
>>
>> The copy of the FDT (aka "duplicate FDT") now belongs to devicetree
>> code, which is thus responsible for freeing the duplicate FDT. The
>> caller of of_overlay_fdt_apply() remains responsible for freeing the
>> original FDT.
>>
>> The unflattened device tree (aka expanded device tree, EDT) now
>> belongs to devicetree code, which is thus responsible for freeing
>> the EDT.
>>
>> These ownership changes prevent early freeing of the duplicated FDT
>> or the EDT, which could result in use after free errors.
>>
>> These changes led to migrating some unittest overlay data into
>> their own devicetree source files, and then converting most of
>> them to use sugar syntax instead of hand coding fragments.
>
> Thanks for your series!
>
>> Frank Rowand (2):
>> of: change overlay apply input data from EDT to FDT
>> of: convert unittest overlay devicetree source to sugar syntax
>
> Do you plan to update Documentation/devicetree/overlay-notes.txt
> and Documentation/devicetree/bindings/fpga/fpga-region.txt, too?

Thanks for the pointers.

I will add updates to Documentation/devicetree/overlay-notes.txt in
this series.

The changes to Documentation/devicetree/bindings/fpga/fpga-region.txt
are related to the relatively new sugar syntax in dtc, not to the
changes introduced by this patch series. I'll create a patch outside
this series to update this documentation.


> Gr{oetje,eeting}s,
>
> Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
>
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
> -- Linus Torvalds
>