On 2/5/21 3:08 PM, Rob Herring wrote:

On Fri, Feb 05, 2021 at 11:17:10AM +0100, Geert Uytterhoeven wrote:

quoted

Hi Viresh,

On Fri, Feb 5, 2021 at 10:55 AM Viresh Kumar [off-list ref] wrote:

quoted

On 05-02-21, 10:41, Geert Uytterhoeven wrote:

quoted

On Fri, Feb 5, 2021 at 10:25 AM Viresh Kumar [off-list ref] wrote:

quoted

On 05-02-21, 10:02, Geert Uytterhoeven wrote:

quoted

Thanks for your patch
(which I only noticed because it appeared in dt-rh/for-next ;-)

On Fri, Jan 29, 2021 at 8:31 AM Viresh Kumar [off-list ref] wrote:

quoted

Add support for building DT overlays (%.dtbo). The overlay's source file
will have the usual extension, i.e. .dts, though the blob will have

Why use .dts and not .dtso for overlays?
Because you originally (until v5) had a single rule for building .dtb
and .dtbo files?

I am fine with doing that as well if Rob and David agree to it. Rob
did suggest that at one point but we didn't do much about it later on
for some reason.

FWIW, this will also require a change in the DTC compiler.

Care to explain why? I've been using .dtsi for ages in
https://git.kernel.org/pub/scm/linux/kernel/git/geert/renesas-drivers.git/log/?h=topic/renesas-overlays

I don't see you building them anywhere, they aren't added to the
Makefile ever. What am I missing ?

actually none of the dtso's were added to any makefile in that branch.

E.g. "ARM: dts: Build all overlays if OF_OVERLAY=y"?
https://git.kernel.org/pub/scm/linux/kernel/git/geert/renesas-drivers.git/commit/?h=topic/renesas-overlays&id=597ee90971687a45678cca8d16bf624d174a99eb

quoted

Anyway, the DTC needs to know how to treat the dtso format and it will
error out currently with unknown format kind of errors.

Below email [1] have some information on the kind of changes required
here. Also note that we had to do similar changes for dtbo earlier
[2].

--
viresh

[1] https://lore.kernel.org/lkml/CAK7LNASViCOTGR7yDTfh0O+PAu+X-P2NwdY4oPMuXrr51awafA@mail.gmail.com/ (local)

-@ is handled by "kbuild: Enable DT symbols when CONFIG_OF_OVERLAY is used"
https://git.kernel.org/pub/scm/linux/kernel/git/geert/renesas-drivers.git/commit/?h=topic/renesas-overlays&id=91e9d998514f3743125a707013a30d5f83054579

quoted

[2] https://lore.kernel.org/lkml/30fd0e5f2156665c713cf191c5fea9a5548360c0.1609926856.git.viresh.kumar@linaro.org/ (local)

I never had a need for those changes to dtc. .dtso/.dtbo work fine regardless.

I think what Viresh means is dtc won't automatically set the input type 
to dts if not .dts.

We stuck with .dtbo as it's already widely used. I don't know about 
dtso though. If there's strong consensus to use .dtso, then let's do 
that. Whatever color for this shed you like.

I overlooked this and mistakenly thought that the move to .dtbo also
involved changing to .dtso.  My bad.

My favorite color here is to use .dtso for the source file that will
be compiled to create a .dtbo.

Linus has already accepted patch 4/6 to 5.12-rc1, so changing to .dtso
will require another patch.

-Frank

Rob