[PATCH] PCI / PM: Avoid using device_may_wakeup() for runtime PM

Rafael J. Wysocki
2017-06-23T00:56:21Z

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

pci_target_state() calls device_may_wakeup() which checks whether
or not the device may wake up the system from sleep states, but
pci_target_state() is used for runtime PM too.

Since runtime PM is expected to always enable remote wakeup if
possible, modify pci_target_state() to take additional argument
indicating whether or not it should look for a state from which
the device can signal wakeup and pass "true" to it from the code
related to runtime PM.

Reported-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
drivers/pci/pci.c | 19 +++++++++++--------
1 file changed, 11 insertions(+), 8 deletions(-)

Index: linux-pm/drivers/pci/pci.c
===================================================================
--- linux-pm.orig/drivers/pci/pci.c
+++ linux-pm/drivers/pci/pci.c
@@ -1982,12 +1982,13 @@ EXPORT_SYMBOL(pci_wake_from_d3);
/**
* pci_target_state - find an appropriate low power state for a given PCI dev
* @dev: PCI device
+ * @wakeup: Whether or not wakeup functionality will be enabled for the device.
*
* Use underlying platform code to find a supported low power state for @dev.
* If the platform can't manage @dev, return the deepest state from which it
* can generate wake events, based on any available PME info.
*/
-static pci_power_t pci_target_state(struct pci_dev *dev)
+static pci_power_t pci_target_state(struct pci_dev *dev, bool wakeup)
{
pci_power_t target_state = PCI_D3hot;

@@ -2024,7 +2025,7 @@ static pci_power_t pci_target_state(stru
if (dev->current_state == PCI_D3cold)
target_state = PCI_D3cold;

- if (device_may_wakeup(&dev->dev)) {
+ if (wakeup) {
/*
* Find the deepest state from which the device can generate
* wake-up events, make it the target state and enable device
@@ -2050,13 +2051,14 @@ static pci_power_t pci_target_state(stru
*/
int pci_prepare_to_sleep(struct pci_dev *dev)
{
- pci_power_t target_state = pci_target_state(dev);
+ bool wakeup = device_may_wakeup(&dev->dev);
+ pci_power_t target_state = pci_target_state(dev, wakeup);
int error;

if (target_state == PCI_POWER_ERROR)
return -EIO;

- pci_enable_wake(dev, target_state, device_may_wakeup(&dev->dev));
+ pci_enable_wake(dev, target_state, wakeup);

error = pci_set_power_state(dev, target_state);

@@ -2089,7 +2091,7 @@ EXPORT_SYMBOL(pci_back_from_sleep);
*/
int pci_finish_runtime_suspend(struct pci_dev *dev)
{
- pci_power_t target_state = pci_target_state(dev);
+ pci_power_t target_state = pci_target_state(dev, true);
int error;

if (target_state == PCI_POWER_ERROR)
@@ -2128,7 +2130,7 @@ bool pci_dev_run_wake(struct pci_dev *de
return false;

/* PME-capable in principle, but not from the intended sleep state */
- if (!pci_pme_capable(dev, pci_target_state(dev)))
+ if (!pci_pme_capable(dev, pci_target_state(dev, true)))
return false;

while (bus->parent) {
@@ -2163,9 +2165,10 @@ EXPORT_SYMBOL_GPL(pci_dev_run_wake);
bool pci_dev_keep_suspended(struct pci_dev *pci_dev)
{
struct device *dev = &pci_dev->dev;
+ bool wakeup = device_may_wakeup(dev);

if (!pm_runtime_suspended(dev)
- || pci_target_state(pci_dev) != pci_dev->current_state
+ || pci_target_state(pci_dev, wakeup) != pci_dev->current_state
|| platform_pci_need_resume(pci_dev)
|| (pci_dev->dev_flags & PCI_DEV_FLAGS_NEEDS_RESUME))
return false;
@@ -2183,7 +2186,7 @@ bool pci_dev_keep_suspended(struct pci_d
spin_lock_irq(&dev->power.lock);

if (pm_runtime_suspended(dev) && pci_dev->current_state < PCI_D3cold &&
- !device_may_wakeup(dev))
+ !wakeup)
__pci_pme_active(pci_dev, false);

spin_unlock_irq(&dev->power.lock);