diff options
Diffstat (limited to 'drivers/pci/probe.c')
| -rw-r--r-- | drivers/pci/probe.c | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 3706ce7972d..aebab71abeb 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -857,6 +857,49 @@ int pci_cfg_space_size_ext(struct pci_dev *dev) return PCI_CFG_SPACE_SIZE; } +/** + * pci_disable_pme - Disable the PME function of PCI device + * @dev: PCI device affected + * -EINVAL is returned if PCI device doesn't support PME. + * Zero is returned if the PME is supported and can be disabled. + */ +static int pci_disable_pme(struct pci_dev *dev) +{ + int pm; + u16 value; + + /* find PCI PM capability in list */ + pm = pci_find_capability(dev, PCI_CAP_ID_PM); + + /* If device doesn't support PM Capabilities, it means that PME is + * not supported. + */ + if (!pm) + return -EINVAL; + /* Check device's ability to generate PME# */ + pci_read_config_word(dev, pm + PCI_PM_PMC, &value); + + value &= PCI_PM_CAP_PME_MASK; + /* Check if it can generate PME# */ + if (!value) { + /* + * If it is zero, it means that PME is still unsupported + * although there exists the PM capability. + */ + return -EINVAL; + } + + pci_read_config_word(dev, pm + PCI_PM_CTRL, &value); + + /* Clear PME_Status by writing 1 to it */ + value |= PCI_PM_CTRL_PME_STATUS ; + /* Disable PME enable bit */ + value &= ~PCI_PM_CTRL_PME_ENABLE; + pci_write_config_word(dev, pm + PCI_PM_CTRL, value); + + return 0; +} + int pci_cfg_space_size(struct pci_dev *dev) { int pos; @@ -964,6 +1007,7 @@ static struct pci_dev *pci_scan_device(struct pci_bus *bus, int devfn) } pci_vpd_pci22_init(dev); + pci_disable_pme(dev); return dev; } |