Merge tag 'pm-5.2-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

2407e486 · Linus Torvalds <[email protected]> · 2019-06-29 19:29:45 +08:00

Pull power management fix from Rafael Wysocki:
 "Avoid skipping bus-level PCI power management during system resume for
  PCIe ports left in D0 during the preceding suspend transition on
  platforms where the power states of those ports can change out of the
  PCI layer's control"

* tag 'pm-5.2-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  PCI: PM: Avoid skipping bus-level PM on platforms without ACPI

Commit: 2407e486066b8ce00dabd7e2b3a2cbcc59ea6186
Parents: 01305db8 · 471a739a

Merge commit. Changes below are compared with the first parent: 01305db8.

Changes

3 files changed · +31 −6

File	Status	Add	Del	Content
drivers/pci/pci-driver.c	modified	+4	−4	View file
include/linux/suspend.h	modified	+24	−2	View file
kernel/power/suspend.c	modified	+3	−0	View file

drivers/pci/pci-driver.c

View file

diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
index 98af9ec..ca37930 100644
--- a/drivers/pci/pci-driver.c
+++ b/drivers/pci/pci-driver.c
@@ -859,7 +859,7 @@ static int pci_pm_suspend_noirq(struct device *dev)
 			pci_dev->bus->self->skip_bus_pm = true;
 	}
 
-	if (pci_dev->skip_bus_pm && !pm_suspend_via_firmware()) {
+	if (pci_dev->skip_bus_pm && pm_suspend_no_platform()) {
 		dev_dbg(dev, "PCI PM: Skipped\n");
 		goto Fixup;
 	}
@@ -914,10 +914,10 @@ static int pci_pm_resume_noirq(struct device *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 may
-	 * confuse some firmware, so avoid doing that.
+	 * configuration here and attempting to put them into D0 again is
+	 * pointless, so avoid doing that.
 	 */
-	if (!pci_dev->skip_bus_pm || pm_suspend_via_firmware())
+	if (!(pci_dev->skip_bus_pm && pm_suspend_no_platform()))
 		pci_pm_default_resume_early(pci_dev);
 
 	pci_fixup_device(pci_fixup_resume_early, pci_dev);

include/linux/suspend.h

View file

diff --git a/include/linux/suspend.h b/include/linux/suspend.h
index 8594001..f0d262a 100644
--- a/include/linux/suspend.h
+++ b/include/linux/suspend.h
@@ -209,8 +209,9 @@ extern int suspend_valid_only_mem(suspend_state_t state);
 
 extern unsigned int pm_suspend_global_flags;
 
-#define PM_SUSPEND_FLAG_FW_SUSPEND	(1 << 0)
-#define PM_SUSPEND_FLAG_FW_RESUME	(1 << 1)
+#define PM_SUSPEND_FLAG_FW_SUSPEND	BIT(0)
+#define PM_SUSPEND_FLAG_FW_RESUME	BIT(1)
+#define PM_SUSPEND_FLAG_NO_PLATFORM	BIT(2)
 
 static inline void pm_suspend_clear_flags(void)
 {
@@ -227,6 +228,11 @@ static inline void pm_set_resume_via_firmware(void)
 	pm_suspend_global_flags |= PM_SUSPEND_FLAG_FW_RESUME;
 }
 
+static inline void pm_set_suspend_no_platform(void)
+{
+	pm_suspend_global_flags |= PM_SUSPEND_FLAG_NO_PLATFORM;
+}
+
 /**
  * pm_suspend_via_firmware - Check if platform firmware will suspend the system.
  *
@@ -268,6 +274,22 @@ static inline bool pm_resume_via_firmware(void)
 	return !!(pm_suspend_global_flags & PM_SUSPEND_FLAG_FW_RESUME);
 }
 
+/**
+ * pm_suspend_no_platform - Check if platform may change device power states.
+ *
+ * To be called during system-wide power management transitions to sleep states
+ * or during the subsequent system-wide transitions back to the working state.
+ *
+ * Return 'true' if the power states of devices remain under full control of the
+ * kernel throughout the system-wide suspend and resume cycle in progress (that
+ * is, if a device is put into a certain power state during suspend, it can be
+ * expected to remain in that state during resume).
+ */
+static inline bool pm_suspend_no_platform(void)
+{
+	return !!(pm_suspend_global_flags & PM_SUSPEND_FLAG_NO_PLATFORM);
+}
+
 /* Suspend-to-idle state machnine. */
 enum s2idle_states {
 	S2IDLE_STATE_NONE,      /* Not suspended/suspending. */

kernel/power/suspend.c

View file

diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index 9505101..0962112 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -493,6 +493,9 @@ int suspend_devices_and_enter(suspend_state_t state)
 
 	pm_suspend_target_state = state;
 
+	if (state == PM_SUSPEND_TO_IDLE)
+		pm_set_suspend_no_platform();
+
 	error = platform_suspend_begin(state);
 	if (error)
 		goto Close;