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PCI / PM: Fix native PME handling during system suspend/resume 

Commit 76cde7e495 (PCI / PM: Make PCIe PME interrupts wake up from
suspend-to-idle) went too far with preventing pcie_pme_work_fn() from
clearing the root port's PME Status and re-enabling the PME interrupt
which should be done for PMEs to work correctly after system resume.

The failing scenario is as follows:

 1. pcie_pme_suspend() finds that the PME IRQ should be designated
    for system wakeup, so it calls enable_irq_wake() and then sets
    data->suspend_level to PME_SUSPEND_WAKEUP.

 2. PME interrupt happens at this point.

 3. pcie_pme_irq() runs, disables the PME interrupt and queues up
    the execution of pcie_pme_work_fn().

 4. pcie_pme_work_fn() runs before pcie_pme_resume() and breaks out
    of the loop right away, because data->suspend_level is not
    PME_SUSPEND_NONE, and it doesn't re-enable the PME interrupt
    for the same reason.

 5. pcie_pme_resume() runs and simply calls disable_irq_wake()
    without re-enabling the PME interrupt (because data->suspend_level
    is not PME_SUSPEND_NONE), so the PME interrupt remains disabled
    and the PME Status remains set.

To fix this notice that there is no reason why pcie_pme_work_fn()
should behave in a special way during system resume if the PME
interrupt is not disabled by pcie_pme_suspend() and partially revert
commit 76cde7e495 and restore the previous (and correct) behavior
of pcie_pme_work_fn().

Fixes: 76cde7e495 (PCI / PM: Make PCIe PME interrupts wake up from suspend-to-idle)
Reported-and-tested-by: Naresh Solanki <naresh.solanki@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
This commit is contained in:
Rafael J. Wysocki 2017-07-06 02:32:02 +02:00
parent 0ce3fcaff9
commit c7b5a4e6e8
1 changed files with 13 additions and 22 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

35
drivers/pci/pcie/pme.c
View File

@ -40,17 +40,11 @@ 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;
enum pme_suspend_level suspend_level;
bool noirq; /* If set, keep the PME interrupt disabled. */
};
/**
@ -228,7 +222,7 @@ static void pcie_pme_work_fn(struct work_struct *work)
spin_lock_irq(&data->lock);
for (;;) {
if (data->suspend_level != PME_SUSPEND_NONE)
if (data->noirq)
break;
pcie_capability_read_dword(port, PCI_EXP_RTSTA, &rtsta);
@ -255,7 +249,7 @@ static void pcie_pme_work_fn(struct work_struct *work)
spin_lock_irq(&data->lock);
}
if (data->suspend_level == PME_SUSPEND_NONE)
if (!data->noirq)
pcie_pme_interrupt_enable(port, true);
spin_unlock_irq(&data->lock);
@ -378,7 +372,7 @@ 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, wake_irq_enabled = false;
bool wakeup;
int ret;
if (device_may_wakeup(&port->dev)) {
@ -388,19 +382,16 @@ static int pcie_pme_suspend(struct pcie_device *srv)
wakeup = pcie_pme_check_wakeup(port->subordinate);
up_read(&pci_bus_sem);
}
spin_lock_irq(&data->lock);
if (wakeup) {
ret = enable_irq_wake(srv->irq);
if (ret == 0) {
data->suspend_level = PME_SUSPEND_WAKEUP;
wake_irq_enabled = true;
}
}
if (!wake_irq_enabled) {
pcie_pme_interrupt_enable(port, false);
pcie_clear_root_pme_status(port);
data->suspend_level = PME_SUSPEND_NOIRQ;
if (!ret)
return 0;
}
spin_lock_irq(&data->lock);
pcie_pme_interrupt_enable(port, false);
pcie_clear_root_pme_status(port);
data->noirq = true;
spin_unlock_irq(&data->lock);
synchronize_irq(srv->irq);
@ -417,15 +408,15 @@ static int pcie_pme_resume(struct pcie_device *srv)
struct pcie_pme_service_data *data = get_service_data(srv);
spin_lock_irq(&data->lock);
if (data->suspend_level == PME_SUSPEND_NOIRQ) {
if (data->noirq) {
struct pci_dev *port = srv->port;
pcie_clear_root_pme_status(port);
pcie_pme_interrupt_enable(port, true);
data->noirq = false;
} else {
disable_irq_wake(srv->irq);
}
data->suspend_level = PME_SUSPEND_NONE;
spin_unlock_irq(&data->lock);
return 0;