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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2019-06-26 00:20:23 +0200
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2019-06-26 23:51:56 +0200
commit471a739a47aa7d582f0cdf9d392957d04632bae2 (patch)
tree2ab59a00c854751954f5d669fda6225a80e70732
parent4b972a01a7da614b4796475f933094751a295a2f (diff)
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PCI: PM: Avoid skipping bus-level PM on platforms without ACPI
There are platforms that do not call pm_set_suspend_via_firmware(), so pm_suspend_via_firmware() returns 'false' on them, but the power states of PCI devices (PCIe ports in particular) are changed as a result of powering down core platform components during system-wide suspend. Thus the pm_suspend_via_firmware() checks in pci_pm_suspend_noirq() and pci_pm_resume_noirq() introduced by commit 3e26c5feed2a ("PCI: PM: Skip devices in D0 for suspend-to- idle") are not sufficient to determine that devices left in D0 during suspend will remain in D0 during resume and so the bus-level power management can be skipped for them. For this reason, introduce a new global suspend flag, PM_SUSPEND_FLAG_NO_PLATFORM, set it for suspend-to-idle only and replace the pm_suspend_via_firmware() checks mentioned above with checks against this flag. Fixes: 3e26c5feed2a ("PCI: PM: Skip devices in D0 for suspend-to-idle") Reported-by: Jon Hunter <jonathanh@nvidia.com> Tested-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
-rw-r--r--drivers/pci/pci-driver.c8
-rw-r--r--include/linux/suspend.h26
-rw-r--r--kernel/power/suspend.c3
3 files changed, 31 insertions, 6 deletions
diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
index 98af9ecd4a90..ca3793002e2f 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);
diff --git a/include/linux/suspend.h b/include/linux/suspend.h
index 8594001e8be8..f0d262ad7b78 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. */
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index 9505101ed2bc..096211299c07 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;