On Thu, Dec 05, 2019 at 10:47:14PM +0530, Sandeep Tripathy wrote:

On Thu, Dec 5, 2019 at 9:54 PM Dan Handley Dan.Handley@arm.com wrote:

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Hi Sandeep

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-----Original Message----- From: TF-A tf-a-bounces@lists.trustedfirmware.org On Behalf Of Sandeep Tripathy via TF-A Sent: 05 December 2019 12:00

My query is more on the spec. The OS (eg: linux) and atf and psci spec seem to have assumed that it is managing an independent system or managing 'all' the masters in a coherent domain. What other reason could possibly encourage to not to follow a shutdown sequence.

Do you mean "to not follow a *graceful* shutdown sequence"?

Yes, exactly. Thanks! If so I can think of 3 reasons:

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1. It's much slower than a non-graceful shutdown.

But this is certainly not a concern for smaller embedded systems.

But we are talking about generic solution here, aren't we ? If so, it remains concern.

[..]

I think you are suggesting to use psci system suspend hook in reboot /power off path Or use system suspend from the OS itself ? Should work.

Just suspend, don't try to use PSCI SYSTEM_SUSPEND in reboot/poweroff path, not at-least in the generic code. If you think it works fine to address your issue, you can use it in your custom solution :)

@Sudeep, I agree alternate approaches to solve data loss problem works and may be those are the best suited.

No, the data loss issue had more open questions and I haven't understood the solution you have there.

The past thread[1] is somewhat related but diverged in multiple directions.

OK, details again ?

-- Regards, Sudeep