Re: [PATCH] nvme-pci: Avoid to go into d3cold if device can't use npss.
From: Christoph Hellwig <hch@lst.de>
Date: 2021-05-25 07:44:32
Also in:
linux-pci, lkml
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"?
quoted hunk ↗ jump to hunk
@@ -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? _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme