[PATCH AUTOSEL for 4.9 192/293] PCI/PM: Avoid using device_may_wakeup() for runtime PM

From: Sasha Levin
Date: Sun Apr 08 2018 - 22:03:27 EST


From: "Rafael J. Wysocki" <rafael.j.wysocki@xxxxxxxxx>

[ Upstream commit 666ff6f83e1db6ed847abf44eb5e3402d82b9350 ]

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 either the return value of device_can_wakeup(), or "false" (if the
device itself is not wakeup-capable) to it from the code related to runtime
PM.

While at it, fix the comment in pci_dev_run_wake() which is not about sleep
states.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Reviewed-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
---
drivers/pci/pci.c | 22 +++++++++++++---------
1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 774b0e2d117b..d6480b30ea8a 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1958,12 +1958,13 @@ 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;

@@ -2000,7 +2001,7 @@ static pci_power_t pci_target_state(struct pci_dev *dev)
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
@@ -2026,13 +2027,14 @@ static pci_power_t pci_target_state(struct pci_dev *dev)
*/
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);

@@ -2065,9 +2067,10 @@ 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;
int error;

+ target_state = pci_target_state(dev, device_can_wakeup(&dev->dev));
if (target_state == PCI_POWER_ERROR)
return -EIO;

@@ -2103,8 +2106,8 @@ bool pci_dev_run_wake(struct pci_dev *dev)
if (!dev->pme_support)
return false;

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

while (bus->parent) {
@@ -2139,9 +2142,10 @@ 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;
@@ -2159,7 +2163,7 @@ bool pci_dev_keep_suspended(struct pci_dev *pci_dev)
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);
--
2.15.1