[PATCH V4 2/2] firmware: ti_sci: Add comment explaining the is_secure code

[Nishanth Menon]

On 17:28-20240130, Dhruva Gole wrote:
> Add a comment to explain the code under is_secure condition of
> ti_sci_do_xfer. This will help avoid confusion amongst people who may in
> future touch upon this code.
> 
> Signed-off-by: Dhruva Gole <d-gole at ti.com>
> ---
>  drivers/firmware/ti_sci.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/drivers/firmware/ti_sci.c b/drivers/firmware/ti_sci.c
> index 49d2696a6d09..d969470b5221 100644
> --- a/drivers/firmware/ti_sci.c
> +++ b/drivers/firmware/ti_sci.c
> @@ -239,6 +239,12 @@ static int ti_sci_do_xfer(struct ti_sci_info *info,
>  	struct ti_sci_secure_msg_hdr *secure_hdr = (struct ti_sci_secure_msg_hdr *)secure_buf;
>  	int ret;
>  
> +	/*
> +	 * The reason why we need the is_secure code is because of boot R5.
> +	 * boot R5 starts off in "secure mode" when it hands off from Boot
> +	 * ROM over to the Secondary bootloader. The initial set of calls
> +	 * we have to make need to be on a secure pipe.
> +	 */
>  	if (info->is_secure) {
>  		/* ToDo: get checksum of the entire message */
>  		secure_hdr->checksum = 0;
> -- 
> 2.34.1
> 

Reviewed-by: Nishanth Menon <nm at ti.com>

-- 
Regards,
Nishanth Menon
Key (0xDDB5849D1736249D) / Fingerprint: F8A2 8693 54EB 8232 17A3  1A34 DDB5 849D 1736 249D