From 3cc2a2b2704f76702cdd417573a934502254276d Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Thu, 5 May 2022 20:16:50 +0200 Subject: [PATCH] PCI/PM: Rearrange pci_set_power_state() The part of pci_set_power_state() related to transitions into low-power states is unnecessary convoluted, so clearly divide it into the D3cold special case and the general case covering all of the other states. Also fix a potential issue with calling pci_bus_set_current_state() to set the current state of all devices on the subordinate bus to D3cold without checking if the power state of the parent bridge has really changed to D3cold. Link: https://lore.kernel.org/r/2139440.Mh6RI2rZIc@kreacher Signed-off-by: Rafael J. Wysocki Signed-off-by: Bjorn Helgaas Reviewed-by: Mika Westerberg --- drivers/pci/pci.c | 28 +++++++++++++++++----------- 1 file changed, 17 insertions(+), 11 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index b6ad2fa354f1..df886098bd60 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1446,19 +1446,25 @@ int pci_set_power_state(struct pci_dev *dev, pci_power_t state) if (state >= PCI_D3hot && (dev->dev_flags & PCI_DEV_FLAGS_NO_D3)) return 0; - /* - * To put device in D3cold, we put device into D3hot in native - * way, then put device into D3cold with platform ops - */ - error = pci_set_low_power_state(dev, state > PCI_D3hot ? - PCI_D3hot : state); + if (state == PCI_D3cold) { + /* + * To put the device in D3cold, put it into D3hot in the native + * way, then put it into D3cold using platform ops. + */ + error = pci_set_low_power_state(dev, PCI_D3hot); - if (pci_platform_power_transition(dev, state)) - return error; + if (pci_platform_power_transition(dev, PCI_D3cold)) + return error; - /* Powering off a bridge may power off the whole hierarchy */ - if (state == PCI_D3cold) - pci_bus_set_current_state(dev->subordinate, PCI_D3cold); + /* Powering off a bridge may power off the whole hierarchy */ + if (dev->current_state == PCI_D3cold) + pci_bus_set_current_state(dev->subordinate, PCI_D3cold); + } else { + error = pci_set_low_power_state(dev, state); + + if (pci_platform_power_transition(dev, state)) + return error; + } return 0; } -- 2.20.1