PM: sleep: core: Do not skip callbacks in the resume phase

The current code in device_resume_noirq() causes the entire early
resume and resume phases of device suspend to be skipped for
devices for which the noirq resume phase have been skipped (due
to the LEAVE_SUSPENDED flag being set) on the premise that those
devices should stay in runtime-suspend after system-wide resume.

However, that may not be correct in two situations.  First, the
middle layer (subsystem) noirq resume callback may be missing for
a given device, but its early resume callback may be present and it
may need to do something even if it decides to skip the driver
callback.  Second, if the device's wakeup settings were adjusted
in the suspend phase without resuming the device (that was in
runtime suspend at that time), they most likely need to be
adjusted again in the resume phase and so the driver callback
in that phase needs to be run.

For the above reason, modify the core to allow the middle layer
->resume_late callback to run even if its ->resume_noirq callback
is missing (and the core has skipped the driver-level callback
in that phase) and to allow all device callbacks to run in the
resume phase.  Also make the core set the PM-runtime status of
devices with SMART_SUSPEND set whose resume callbacks are not
skipped to "active" in the "noirq" resume phase and update the
affected subsystems (PCI and ACPI) accordingly.

After this change, middle-layer (subsystem) callbacks will always
be invoked in all phases of system suspend and resume and driver
callbacks will always run in the prepare, suspend, resume, and
complete phases for all devices.

For devices with SMART_SUSPEND set, driver callbacks will be
skipped in the late and noirq phases of system suspend if those
devices remain in runtime suspend in __device_suspend_late().
Driver callbacks will also be skipped for them during the
noirq and early phases of the "thaw" transition related to
hibernation in that case.

Setting LEAVE_SUSPENDED means that the driver allows its callbacks
to be skipped in the noirq and early phases of system resume, but
some additional conditions need to be met for that to happen (among
other things, the power.may_skip_resume flag needs to be set for the
device during system suspend for the driver callbacks to be skipped
during the subsequent resume transition).

For all devices with SMART_SUSPEND set whose driver callbacks are
invoked during system resume, the PM-runtime status will be set to
"active" (by the core).

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>

1 files changed, 10 insertions, 8 deletions

diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
index 0454ca0e4e3f..685fbf044911 100644
--- a/drivers/pci/pci-driver.c
+++ b/drivers/pci/pci-driver.c
@@ -897,14 +897,6 @@ static int pci_pm_resume_noirq(struct device *dev)
 		return 0;
 
 	/*
-	 * Devices with DPM_FLAG_SMART_SUSPEND may be left in runtime suspend
-	 * during system suspend, so update their runtime PM status to "active"
-	 * as they are going to be put into D0 shortly.
-	 */
-	if (dev_pm_smart_suspend_and_suspended(dev))
-		pm_runtime_set_active(dev);
-
-	/*
 	 * In the suspend-to-idle case, devices left in D0 during suspend will
 	 * stay in D0, so it is not necessary to restore or update their
 	 * configuration here and attempting to put them into D0 again is
@@ -928,6 +920,14 @@ static int pci_pm_resume_noirq(struct device *dev)
 	return 0;
 }
 
+static int pci_pm_resume_early(struct device *dev)
+{
+	if (dev_pm_may_skip_resume(dev))
+		return 0;
+
+	return pm_generic_resume_early(dev);
+}
+
 static int pci_pm_resume(struct device *dev)
 {
 	struct pci_dev *pci_dev = to_pci_dev(dev);
@@ -961,6 +961,7 @@ static int pci_pm_resume(struct device *dev)
 #define pci_pm_suspend_late	NULL
 #define pci_pm_suspend_noirq	NULL
 #define pci_pm_resume		NULL
+#define pci_pm_resume_early	NULL
 #define pci_pm_resume_noirq	NULL
 
 #endif /* !CONFIG_SUSPEND */
@@ -1358,6 +1359,7 @@ static const struct dev_pm_ops pci_dev_pm_ops = {
 	.suspend = pci_pm_suspend,
 	.suspend_late = pci_pm_suspend_late,
 	.resume = pci_pm_resume,
+	.resume_early = pci_pm_resume_early,
 	.freeze = pci_pm_freeze,
 	.thaw = pci_pm_thaw,
 	.poweroff = pci_pm_poweroff,