Re: Query related to shutting down NVMe during system suspend

nitirawa
2022-02-07T11:09:10Z

On 2022-02-01 22:28, Vidya Sagar wrote:
> 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...
>>

Hi Vidya,

Are you planning to add module parameter based on above discussion. I
see similar behaviour even with qualcomm platform.

[ 119.994092] nvme nvme0: I/O 9 QID 0 timeout, reset controller
[ 120.006612] PM: dpm_run_callback(): pci_pm_resume+0x0/0xe4 returns
-16
[ 120.013502] nvme 0001:01:00.0: PM: pci_pm_resume+0x0/0xe4 returned
-16 after 60059958 usecs
[ 120.022239] nvme 0001:01:00.0: PM: failed to resume async: error -16

Regards,
Nitin