diff options
| author | Rafael J. Wysocki <rjw@sisk.pl> | 2010-02-18 01:36:58 +0300 |
|---|---|---|
| committer | Jesse Barnes <jbarnes@virtuousgeek.org> | 2010-02-23 03:20:24 +0300 |
| commit | 58ff463396ad00828e922d50998787e97fd32512 (patch) | |
| tree | 4964b07518a02736a23839d89bb7ac4a065dede8 | |
| parent | 6d3be84aab461815978d970aa45f5bc9e52dd772 (diff) | |
| download | linux-58ff463396ad00828e922d50998787e97fd32512.tar.xz | |
PCI PM: Add function for checking PME status of devices
Add function pci_check_pme_status() that will check the PME status
bit of given device and clear it along with the PME enable bit. It
will be necessary for PCI run-time power management.
Based on a patch from Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
| -rw-r--r-- | drivers/pci/pci.c | 35 | ||||
| -rw-r--r-- | drivers/pci/pci.h | 1 |
2 files changed, 36 insertions, 0 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 1f9be53c39ba..5723446544fd 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1195,6 +1195,41 @@ int pci_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state) } /** + * pci_check_pme_status - Check if given device has generated PME. + * @dev: Device to check. + * + * Check the PME status of the device and if set, clear it and clear PME enable + * (if set). Return 'true' if PME status and PME enable were both set or + * 'false' otherwise. + */ +bool pci_check_pme_status(struct pci_dev *dev) +{ + int pmcsr_pos; + u16 pmcsr; + bool ret = false; + + if (!dev->pm_cap) + return false; + + pmcsr_pos = dev->pm_cap + PCI_PM_CTRL; + pci_read_config_word(dev, pmcsr_pos, &pmcsr); + if (!(pmcsr & PCI_PM_CTRL_PME_STATUS)) + return false; + + /* Clear PME status. */ + pmcsr |= PCI_PM_CTRL_PME_STATUS; + if (pmcsr & PCI_PM_CTRL_PME_ENABLE) { + /* Disable PME to avoid interrupt flood. */ + pmcsr &= ~PCI_PM_CTRL_PME_ENABLE; + ret = true; + } + + pci_write_config_word(dev, pmcsr_pos, pmcsr); + + return ret; +} + +/** * pci_pme_capable - check the capability of PCI device to generate PME# * @dev: PCI device to handle. * @state: PCI state from which device will issue PME#. diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 5d169bc3ccd1..b95b0a077d31 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -49,6 +49,7 @@ struct pci_platform_pm_ops { extern int pci_set_platform_pm(struct pci_platform_pm_ops *ops); extern void pci_update_current_state(struct pci_dev *dev, pci_power_t state); extern void pci_disable_enabled_device(struct pci_dev *dev); +extern bool pci_check_pme_status(struct pci_dev *dev); extern void pci_pm_init(struct pci_dev *dev); extern void platform_pci_wakeup_init(struct pci_dev *dev); extern void pci_allocate_cap_save_buffers(struct pci_dev *dev); |