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Commit 0f64474b authored by David Shaohua Li's avatar David Shaohua Li Committed by Len Brown
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[ACPI] PCI can now get suspend state from firmware 

pci_choose_state() can now call
	platform_pci_choose_state()
		and ACPI can answer

http://bugzilla.kernel.org/show_bug.cgi?id=4277



Signed-off-by: default avatarDavid Shaohua Li <shaohua.li@intel.com>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent 84df749f

drivers/pci/pci-acpi.c

+46 −1
Original line number Diff line number Diff line 
/*

 * File:	pci-acpi.c

 * Purpose:	Provide PCI support in ACPI

 * Purpose:	Provde PCI support in ACPI

 *

 * Copyright (C) 2005 David Shaohua Li <shaohua.li@intel.com>

 * Copyright (C) 2004 Tom Long Nguyen <tom.l.nguyen@intel.com>
@@ -17,6 +17,7 @@ 
#include <acpi/acpi_bus.h>



#include <linux/pci-acpi.h>

#include "pci.h"



static u32 ctrlset_buf[3] = {0, 0, 0};

static u32 global_ctrlsets = 0;
@@ -209,6 +210,49 @@ acpi_status pci_osc_control_set(u32 flags) 
}

EXPORT_SYMBOL(pci_osc_control_set);



/*

 * _SxD returns the D-state with the highest power

 * (lowest D-state number) supported in the S-state "x".

 *

 * If the devices does not have a _PRW

 * (Power Resources for Wake) supporting system wakeup from "x"

 * then the OS is free to choose a lower power (higher number

 * D-state) than the return value from _SxD.

 *

 * But if _PRW is enabled at S-state "x", the OS

 * must not choose a power lower than _SxD --

 * unless the device has an _SxW method specifying

 * the lowest power (highest D-state number) the device

 * may enter while still able to wake the system.

 *

 * ie. depending on global OS policy:

 *

 * if (_PRW at S-state x)

 *	choose from highest power _SxD to lowest power _SxW

 * else // no _PRW at S-state x

 * 	choose highest power _SxD or any lower power

 *

 * currently we simply return _SxD, if present.

 */



static int acpi_pci_choose_state(struct pci_dev *pdev, pm_message_t state)

{

	char dstate_str[] = "_S0D";

	acpi_status status;

	unsigned long val;

	struct device *dev = &pdev->dev;



	/* Fixme: the check is wrong after pm_message_t is a struct */

	if ((state >= PM_SUSPEND_MAX) || !DEVICE_ACPI_HANDLE(dev))

		return -EINVAL;

	dstate_str[2] += state;	/* _S1D, _S2D, _S3D, _S4D */

	status = acpi_evaluate_integer(DEVICE_ACPI_HANDLE(dev), dstate_str,

		NULL, &val);

	if (ACPI_SUCCESS(status))

		return val;

	return -ENODEV;

}



/* ACPI bus type */

static int pci_acpi_find_device(struct device *dev, acpi_handle *handle)

{
@@ -255,6 +299,7 @@ static int __init pci_acpi_init(void) 
	ret = register_acpi_bus_type(&pci_acpi_bus);

	if (ret)

		return 0;

	platform_pci_choose_state = acpi_pci_choose_state;

	return 0;

}

arch_initcall(pci_acpi_init);

drivers/pci/pci.c

+10 −1
Original line number Diff line number Diff line
@@ -304,6 +304,8 @@ pci_set_power_state(struct pci_dev *dev, pci_power_t state) 
	return 0;

}



int (*platform_pci_choose_state)(struct pci_dev *dev, pm_message_t state) = NULL;

 

/**

 * pci_choose_state - Choose the power state of a PCI device

 * @dev: PCI device to be suspended
@@ -316,9 +318,16 @@ pci_set_power_state(struct pci_dev *dev, pci_power_t state) 


pci_power_t pci_choose_state(struct pci_dev *dev, pm_message_t state)

{

	int ret;



	if (!pci_find_capability(dev, PCI_CAP_ID_PM))

		return PCI_D0;



	if (platform_pci_choose_state) {

		ret = platform_pci_choose_state(dev, state);

		if (ret >= 0)

			state = ret;

	}

 	switch (state) {

	case 0: return PCI_D0;

	case 3: return PCI_D3hot;

drivers/pci/pci.h

+3 −0
Original line number Diff line number Diff line
@@ -11,6 +11,9 @@ extern int pci_bus_alloc_resource(struct pci_bus *bus, struct resource *res, 
				  void (*alignf)(void *, struct resource *,

					  	 unsigned long, unsigned long),

				  void *alignf_data);

/* Firmware callbacks */

extern int (*platform_pci_choose_state)(struct pci_dev *dev, pm_message_t state);



/* PCI /proc functions */

#ifdef CONFIG_PROC_FS

extern int pci_proc_attach_device(struct pci_dev *dev);