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Commit 76cde7e4 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki
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PCI / PM: Make PCIe PME interrupts wake up from suspend-to-idle 



To make PCIe PME interrupts wake up the system from suspend to idle,
make the PME driver use enable_irq_wake() on the IRQ during system
suspend (if there are any wakeup devices below the given PCIe port)
without disabling PME interrupts.  This way, an interrupt will still
trigger if a wakeup event happens and the system will be woken up (or
system suspend in progress will be aborted) by means of the new
mechanics introduced previously.

This change allows Wake-on-LAN to be used for wakeup from
suspend-to-idle on my MSI Wind tesbed netbook.

Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 5613570b

drivers/pci/pcie/pme.c

+51 −10
Original line number Diff line number Diff line
@@ -41,11 +41,17 @@ static int __init pcie_pme_setup(char *str) 
}

__setup("pcie_pme=", pcie_pme_setup);



enum pme_suspend_level {

	PME_SUSPEND_NONE = 0,

	PME_SUSPEND_WAKEUP,

	PME_SUSPEND_NOIRQ,

};



struct pcie_pme_service_data {

	spinlock_t lock;

	struct pcie_device *srv;

	struct work_struct work;

	bool noirq; /* Don't enable the PME interrupt used by this service. */

	enum pme_suspend_level suspend_level;

};



/**
@@ -223,7 +229,7 @@ static void pcie_pme_work_fn(struct work_struct *work) 
	spin_lock_irq(&data->lock);



	for (;;) {

		if (data->noirq)

		if (data->suspend_level != PME_SUSPEND_NONE)

			break;



		pcie_capability_read_dword(port, PCI_EXP_RTSTA, &rtsta);
@@ -250,7 +256,7 @@ static void pcie_pme_work_fn(struct work_struct *work) 
		spin_lock_irq(&data->lock);

	}



	if (!data->noirq)

	if (data->suspend_level == PME_SUSPEND_NONE)

		pcie_pme_interrupt_enable(port, true);



	spin_unlock_irq(&data->lock);
@@ -367,6 +373,21 @@ static int pcie_pme_probe(struct pcie_device *srv) 
	return ret;

}



static bool pcie_pme_check_wakeup(struct pci_bus *bus)

{

	struct pci_dev *dev;



	if (!bus)

		return false;



	list_for_each_entry(dev, &bus->devices, bus_list)

		if (device_may_wakeup(&dev->dev)

		    || pcie_pme_check_wakeup(dev->subordinate))

			return true;



	return false;

}



/**

 * pcie_pme_suspend - Suspend PCIe PME service device.

 * @srv: PCIe service device to suspend.
@@ -375,11 +396,26 @@ static int pcie_pme_suspend(struct pcie_device *srv) 
{

	struct pcie_pme_service_data *data = get_service_data(srv);

	struct pci_dev *port = srv->port;

	bool wakeup;



	if (device_may_wakeup(&port->dev)) {

		wakeup = true;

	} else {

		down_read(&pci_bus_sem);

		wakeup = pcie_pme_check_wakeup(port->subordinate);

		up_read(&pci_bus_sem);

	}

	spin_lock_irq(&data->lock);

	if (wakeup) {

		enable_irq_wake(srv->irq);

		data->suspend_level = PME_SUSPEND_WAKEUP;

	} else {

		struct pci_dev *port = srv->port;



		pcie_pme_interrupt_enable(port, false);

		pcie_clear_root_pme_status(port);

	data->noirq = true;

		data->suspend_level = PME_SUSPEND_NOIRQ;

	}

	spin_unlock_irq(&data->lock);



	synchronize_irq(srv->irq);
@@ -394,12 +430,17 @@ static int pcie_pme_suspend(struct pcie_device *srv) 
static int pcie_pme_resume(struct pcie_device *srv)

{

	struct pcie_pme_service_data *data = get_service_data(srv);

	struct pci_dev *port = srv->port;



	spin_lock_irq(&data->lock);

	data->noirq = false;

	if (data->suspend_level == PME_SUSPEND_NOIRQ) {

		struct pci_dev *port = srv->port;



		pcie_clear_root_pme_status(port);

		pcie_pme_interrupt_enable(port, true);

	} else {

		disable_irq_wake(srv->irq);

	}

	data->suspend_level = PME_SUSPEND_NONE;

	spin_unlock_irq(&data->lock);



	return 0;