From 907a7a2e5bf40c6a359b2f6cc53d6fdca04009e0 Mon Sep 17 00:00:00 2001 From: Mario Limonciello Date: Wed, 11 Jun 2025 18:31:16 -0500 Subject: [PATCH] PCI/PM: Set up runtime PM even for devices without PCI PM 4d4c10f763d7 ("PCI: Explicitly put devices into D0 when initializing") intended to put PCI devices into D0, but in doing so unintentionally changed runtime PM initialization not to occur on devices that don't support PCI PM. This caused a regression in vfio-pci due to an imbalance with its use. Adjust the logic in pci_pm_init() so that even if PCI PM isn't supported runtime PM is still initialized. Fixes: 4d4c10f763d7 ("PCI: Explicitly put devices into D0 when initializing") Reported-by: Giovanni Cabiddu Closes: https://lore.kernel.org/linux-pci/20250424043232.1848107-1-superm1@kernel.org/T/#m7e8929d6421690dc8bd6dc639d86c2b4db27cbc4 Reported-by: Nicolas Dichtel Closes: https://lore.kernel.org/linux-pci/20250424043232.1848107-1-superm1@kernel.org/T/#m40d277dcdb9be64a1609a82412d1aa906263e201 Signed-off-by: Mario Limonciello Signed-off-by: Bjorn Helgaas Tested-by: Giovanni Cabiddu Tested-by: Nicolas Dichtel Reviewed-by: Kuppuswamy Sathyanarayanan Acked-by: Rafael J. Wysocki Cc: Alex Williamson Link: https://patch.msgid.link/20250611233117.61810-1-superm1@kernel.org --- drivers/pci/pci.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index e9448d55113b..9e42090fb108 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -3217,14 +3217,14 @@ void pci_pm_init(struct pci_dev *dev) /* find PCI PM capability in list */ pm = pci_find_capability(dev, PCI_CAP_ID_PM); if (!pm) - return; + goto poweron; /* Check device's ability to generate PME# */ pci_read_config_word(dev, pm + PCI_PM_PMC, &pmc); if ((pmc & PCI_PM_CAP_VER_MASK) > 3) { pci_err(dev, "unsupported PM cap regs version (%u)\n", pmc & PCI_PM_CAP_VER_MASK); - return; + goto poweron; } dev->pm_cap = pm; @@ -3269,6 +3269,7 @@ void pci_pm_init(struct pci_dev *dev) pci_read_config_word(dev, PCI_STATUS, &status); if (status & PCI_STATUS_IMM_READY) dev->imm_ready = 1; +poweron: pci_pm_power_up_and_verify_state(dev); pm_runtime_forbid(&dev->dev); pm_runtime_set_active(&dev->dev); -- 2.50.1