diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 2e18e9adcc15..b2be8957a290 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -707,26 +707,25 @@ static int pci_raw_set_power_state(struct pci_dev *dev, pci_power_t state) } /** - * pci_update_current_state - Read PCI power state of given device from its - * PCI PM registers and cache it + * pci_update_current_state - Read power state of given device and cache it * @dev: PCI device to handle. * @state: State to cache in case the device doesn't have the PM capability + * + * The power state is read from the PMCSR register, which however is + * inaccessible in D3cold. The platform firmware is therefore queried first + * to detect accessibility of the register. In case the platform firmware + * reports an incorrect state or the device isn't power manageable by the + * platform at all, we try to detect D3cold by testing accessibility of the + * vendor ID in config space. */ void pci_update_current_state(struct pci_dev *dev, pci_power_t state) { - if (dev->pm_cap) { + if (platform_pci_get_power_state(dev) == PCI_D3cold || + !pci_device_is_present(dev)) { + dev->current_state = PCI_D3cold; + } else if (dev->pm_cap) { u16 pmcsr; - /* - * Configuration space is not accessible for device in - * D3cold, so just keep or set D3cold for safety - */ - if (dev->current_state == PCI_D3cold) - return; - if (state == PCI_D3cold) { - dev->current_state = PCI_D3cold; - return; - } pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr); dev->current_state = (pmcsr & PCI_PM_CTRL_STATE_MASK); } else {