[PATCH] drivers: firmware: ti_sci: Add DM_FLAG_PRE_RELOC to driver

[Manorit Chawdhry]

Hi Tom,

On 08:53-20241217, Tom Rini wrote:
> On Tue, Dec 17, 2024 at 02:24:37PM +0530, Manorit Chawdhry wrote:
> 
> > Currently the driver relies on bootph flag to probe it during PRE_RELOC
> > stage but with the upcoming cleanup of v6.13, we don't have the bootph
> > property in the parent nodes anymore and ti_sci driver being one of the
> > parent nodes required during SPL stage would end up hampering the probe
> > model [0].
> > 
> > Add DM_FLAG_PRE_RELOC to ti_sci driver for mitigating this issue.
> 
> 
> Can you please expand on why with v6.13 we don't have the flag anymore?
> Thanks.

So the idea was that following series [0] would help us cleanup all the
parent node bootph-* tags as putting a bootph-* in child node implies
that it applies to parent nodes as well, though even if the parent node
gets packed after the following series, the parent node still don't get
probed as from my understanding, we need bootph-* tag to probe the
driver as well but the phase tag doesn't get propagated as such.

So while working in Linux, some comments related to this was raised [1]
and after confirming the behaviour with Simon [2], the cleanup was done
in Linux and meanwhile this way was found to probe the driver so that
even after cleaning up the parent bootph-* tags we can continue.

I don't think it's a hack also as this driver is required pre-relocation
and this is another way to probe it pre-relocation but the only thing is
that since the cleanup is done right now, we would kind of need it to be
booting in some platforms ( that were fully reliant on Linux DT and
don't have -u-boot override for this particular node with bootph-* )
before 6.13 DT gets synced up.

[0]: https://lore.kernel.org/u-boot/20231217163627.2339802-1-sjg@chromium.org/
[1]: https://lore.kernel.org/all/20240709084857.nf7c57mi6miajeau@uda0497581/#t
[2]: https://lore.kernel.org/u-boot/CAFLszTjr7bJFPnyVx7rTdFB3AFBM_2DVAZU8FZnLBE7ep5ejXw@mail.gmail.com/

Regards,
Manorit

> 
> -- 
> Tom