Commit 224abb67 authored Jun 17, 2016 by Bjorn Helgaas

PCI: Document connection between pci_power_t and hardware PM capability



The dev.pme_support field, pci_pm_init(), pci_pme_capable(), and
pci_raw_set_power_state() depend on the fact that the pci_power_t values
(PCI_D0, PCI_D1, etc.) match the definition of the Capabilities PME_Support
and the Control/Status PowerState fields in the Power Management capability
(see PCI Bus Power Management spec r1.2, sec 3.2.3).

Add a note to this effect at the pci_power_t typedef.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

parent 006d44e4

include/linux/pci.h

+4 −0

Original line number	Diff line number	Diff line
		@@ -101,6 +101,10 @@ enum {
		DEVICE_COUNT_RESOURCE = PCI_NUM_RESOURCES,
		};

		/*
		* pci_power_t values must match the bits in the Capabilities PME_Support
		* and Control/Status PowerState fields in the Power Management capability.
		*/
		typedef int __bitwise pci_power_t;

		#define PCI_D0 ((pci_power_t __force) 0)

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