Hi Mark,

On Thu, Jan 18, 2024 at 4:23 PM Mark Rutland [off-list ref] wrote:

On Tue, Jan 16, 2024 at 03:13:42PM +0100, Geert Uytterhoeven wrote:

quoted

On Tue, Jan 16, 2024 at 12:51 PM Mark Rutland [off-list ref] wrote:

quoted

On Fri, Jan 12, 2024 at 12:07:44PM -0800, Stephen Boyd wrote:

quoted

Call this function unconditionally so that we can populate an empty DTB
on platforms that don't boot with a firmware provided or builtin DTB.
There's no harm in calling unflatten_device_tree() unconditionally.

For better or worse, that's not true: there are systems the provide both a DTB
*and* ACPI tables, and we must not consume both at the same time as those can
clash and cause all sorts of problems. In addition, we don't want people being
"clever" and describing disparate portions of their system in ACPI and DT.

We'd get to the latter anyway, when plugging in a USB device where the
circuitry on/behind the USB device is described in DT.

I don't understand what you mean there; where is the DT description of the USB
device coming from if the DTB hasn't been unflattened?

Either stored in (FLASH) ROM on the USB device, or loaded from
/lib/firmware/.  In both cases that would be handled by the USB driver
for the device.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

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

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