[PATCH V3] firmware: ti_sci: fix the secure_hdr in do_xfer

[Dhruva Gole]

On Jan 24, 2024 at 12:09:06 -0600, Nishanth Menon wrote:
> On 18:37-20240124, Dhruva Gole wrote:
> > The secure_hdr needs to be 0 init-ed however this was never being put
> > into the secure_buf, leading to possibility of the first 4 bytes of
> > secure_buf being possibly garbage.
> > 
> > Fix this by initialising the secure_hdr itself to the secure_buf
> > location, thus when we make it 0, it automatically ensures the first 4
> > bytes are 0.
> > 
> > Fixes: 32cd25128bd849 ("firmware: Add basic support for TI System Control Interface (TI SCI)")
> > Signed-off-by: Dhruva Gole <d-gole at ti.com>
> > ---
> > 
> > Boot tested for sanity on AM62x SK
> > https://gist.github.com/DhruvaG2000/724ceba3a0db03f4b0bff47de1160074
> > 
> > Changelog:
> > v2 --> v3
> > Address Kamlesh's comment on v2: use sizeof(struct ti_sci_secure_msg_hdr)
> 
> Lets finish discussing in:
> https://lore.kernel.org/all/20240124163910.sp7gt56lihoujm7k@etching/

Bringing the conversation back to this latest patch revision,
Based on where we left off:
https://lore.kernel.org/all/20240125171335.qoxphnemadkh7xjd@gullible/

Would it be better to add a comment above ``if (info->is_secure) {`` in
drivers/firmware/ti_sci.c as follows:
The secure path will be used by R5 SPL bcause it starts of in "secure mode" when it hands
off from Boot ROM over to the Secondary bootloader.

Kindly advise if the patch needs respin with that minor change, and if the rest
of it seems okay?

-- 
Best regards,
Dhruva Gole <d-gole at ti.com>