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Commit 58ff4633 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki Committed by Jesse Barnes
Browse files

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: default avatarRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: default avatarJesse Barnes <jbarnes@virtuousgeek.org>
parent 6d3be84a

drivers/pci/pci.c

+35 −0
Original line number Diff line number Diff line
@@ -1194,6 +1194,41 @@ int pci_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state) 
	return pcibios_set_pcie_reset_state(dev, 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.

drivers/pci/pci.h

+1 −0
Original line number Diff line number Diff line
@@ -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);