Re: [PATCH v2] arm64: Disallow disabling boot CPU based on config

[Daniel Lezcano <daniel.lezcano@oss.qualcomm.com>]

[ Cc'ed Maulik ]


On 7/6/26 11:16, Sudeep Holla wrote:
> On Sat, Jul 04, 2026 at 08:43:39AM +0200, Daniel Lezcano wrote:
>>
>> Hi Sudeep,
>>
>> Le 03/07/2026 à 17:51, Sudeep Holla a écrit :
>>> (It is always good to cc all PSCI maintainer for any ARM64 CPU
>>> hotpug/suspend related changes)
>>>
>>> On Fri, Jul 03, 2026 at 04:50:02PM +0530, Sneh Mankad wrote:
>>>> The Qualcomm SoCs like LeMans, Monaco support suspend to ram which leads
>>>> the SoC to ACPI S3 similar state where SoC is turned off and DDR is
>>>> retained. The hardware design on these SoCs forces a constraint to suspend
>>>> and resume the system on boot CPU / CPU0.
>>>>
>>> And you fail to explain why they have that constraint.
>>>
> 
> I still need the above to understand the issue/constraint better.

Ok, I think Maulik can give some details here.

>>> Is it because some secure context is not allowed to migrate ?
>>>
>>> We already have a mechanism for that in place and this hack is not at all
>>> required.
>> Do you mean a mechanism for the secure context or for preventing CPU0 ?
>>
> 
> I meant constraint based on secure context.
>