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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2017-07-06 02:32:02 +0200
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2017-07-13 01:50:07 +0200
commitc7b5a4e6e8fbef8fdf2c529f953000d24c561339 (patch)
treecfcfbc878ad716b3bd39cc8b0edce09d462caf1b /drivers/pci
parent0ce3fcaff92908c370334ce3b9111aeea71159d6 (diff)
PCI / PM: Fix native PME handling during system suspend/resume
Commit 76cde7e49590 (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 76cde7e49590 and restore the previous (and correct) behavior of pcie_pme_work_fn(). Fixes: 76cde7e49590 (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>
Diffstat (limited to 'drivers/pci')
-rw-r--r--drivers/pci/pcie/pme.c35
1 files changed, 13 insertions, 22 deletions
diff --git a/drivers/pci/pcie/pme.c b/drivers/pci/pcie/pme.c
index 80e58d25006d..fafdb165dd2e 100644
--- a/drivers/pci/pcie/pme.c
+++ b/drivers/pci/pcie/pme.c
@@ -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;