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Date:   Thu, 10 Feb 2022 09:41:04 +0530
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Subject: Re: Query related to shutting down NVMe during system suspend
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To:     Keith Busch <kbusch@kernel.org>, <robh+dt@kernel.org>
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From:   Vidya Sagar <vidyas@nvidia.com>
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On 2/10/2022 1:56 AM, Keith Busch wrote:
> External email: Use caution opening links or attachments
> 
> 
> On Tue, Feb 01, 2022 at 09:52:28PM +0530, Vidya Sagar wrote:
>> Hi Rafael & Christoph,
>> My query is regarding the comment and the code that follows after it at
>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/nvme/host/pci.c?h=v5.17-rc2#n3243
>> What I understood from it is that, there is an underlying assumption
>> that the power to the devices is not removed during the suspend call.
>> In the case of device-tree based platforms like Tegra194, power is
>> indeed removed to the devices during suspend-resume process. Hence, the
>> NVMe devices need to be taken through the shutdown path irrespective of
>> whether the ASPM states are enabled or not.
>> I would like to hear from you the best method to follow to achieve this.
> 
> Christoph prefers to append quirks for platforms that need full device
> shutdown on s2idle instead of changing the driver default.
> 
> We use dmi matching for our current platform quirk list. I do not know
> what the equivalent is for device-tree based platforms. Do you know?
I'm afraid I don't.
Rob, could you please help here?

>