On Mon, Jan 11, 2021 at 5:19 PM Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> wrote:
> > I suppose we already had a discussion of why this property
> > is undocumented? Or should we document it? Obviously
> > it is already in widespread use.
>
> This comes from commit 51975db0b7333cf3 ("of/flattree: merge
> early_init_dt_scan_memory() common code"), which combined existing
> practises on Microblaze (commit 12e8414263f47352 ("microblaze_v8: Open
> firmware files")) and PowerPC (ba7594852f4e7121 ("[PATCH] powerpc: Add
> support for "linux,usable-memory" on memory nodes")), with the former
> obviously just copying the latter.
> Unfortunately none of this is documented in The DeviceTree
> Specification, ePAPR, or P1275.
>
> Heinrich tried to document it, but his patch was ignored:
> [PATCH] Documentation: devicetree: "linux,usable-memory" property
> https://lore.kernel.org/linux-devicetree/20161223161747.9986-1-xypron.glpk@xxxxxx/
> https://lkml.org/lkml/2016/12/23/175
> https://lore.kernel.org/patchwork/patch/745784/
> Note that Heinrichs address is mangled in lore (imported from gmane?,
> but lkml and patchwork have it right.
I bet it's just a mishap.
Rob, can you pick up and apply this patch?
Yours,
Linus Walleij
