Messages in this thread | | | Date | Tue, 25 May 2021 09:44:26 +0200 | From | Christoph Hellwig <> | Subject | Re: [PATCH] nvme-pci: Avoid to go into d3cold if device can't use npss. |
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On Thu, May 20, 2021 at 11:33:15AM +0800, Koba Ko wrote: > After resume, host can't change power state of the closed controller > from D3cold to D0.
Why?
> For these devices, just avoid to go deeper than d3hot.
What are "these devices"?
> @@ -2958,6 +2959,15 @@ static int nvme_probe(struct pci_dev *pdev, const struct pci_device_id *id) > > dev_info(dev->ctrl.device, "pci function %s\n", dev_name(&pdev->dev)); > > + if (pm_suspend_via_firmware() || !dev->ctrl.npss || > + !pcie_aspm_enabled(pdev) || > + dev->nr_host_mem_descs || > + (dev->ctrl.quirks & NVME_QUIRK_SIMPLE_SUSPEND)) {
Before we start open coding this in even more places we really want a little helper function for these checks, which should be accomodated with the comment near the existing copy of the checks.
> + pdev->d3cold_allowed = false; > + pci_d3cold_disable(pdev); > + pm_runtime_resume(&pdev->dev);
Why do we need to both set d3cold_allowed and call pci_d3cold_disable?
What is the pm_runtime_resume doing here?
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