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From: Vidya Sagar <vidyas@nvidia.com>
To: Keith Busch <kbusch@kernel.org>
Cc: <rafael.j.wysocki@intel.com>, <hch@lst.de>, <bhelgaas@google.com>,
	<mmaddireddy@nvidia.com>, <kthota@nvidia.com>,
	<sagar.tv@gmail.com>, <linux-pci@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>
Subject: Re: Query related to shutting down NVMe during system suspend
Date: Tue, 1 Feb 2022 22:28:44 +0530	[thread overview]
Message-ID: <0bd9fdc1-99d4-1c59-7343-3708b331b2b5@nvidia.com> (raw)
In-Reply-To: <20220201163054.GA2838889@dhcp-10-100-145-180.wdc.com>

Thanks for the super quick reply and I couldn't agree more.

On 2/1/2022 10:00 PM, 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.
> 
> Since platform makers can't converge on how to let a driver know what
> it's supposed to do, I suggest we default to the simple shutdown suspend
> all the time. We can add a module parameter to let a user request nvme
> power management if they really want it. No matter what we do here,
> someone is going to complain, but at least simple shutdown is safe...
> 

  reply	other threads:[~2022-02-01 16:58 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-02-01 16:22 Query related to shutting down NVMe during system suspend Vidya Sagar
2022-02-01 16:30 ` Keith Busch
2022-02-01 16:58   ` Vidya Sagar [this message]
2022-02-07 10:57     ` nitirawa
2022-02-07 12:11       ` Vidya Sagar
2022-02-07 15:44         ` nitirawa
2022-02-07 15:47           ` Keith Busch
2022-02-01 17:17   ` Rafael J. Wysocki
2022-02-09 20:26 ` Keith Busch
2022-02-09 21:17   ` nitirawa
2022-02-09 21:47     ` Keith Busch
2022-02-10  4:11   ` Vidya Sagar
2022-02-10  5:40     ` Lukas Wunner
2022-02-10 12:36       ` nitirawa

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