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authorLinus Torvalds <torvalds@linux-foundation.org>2019-06-19 11:44:04 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-06-19 11:44:04 -0700
commitabf02e2964b3aaf1d5197c5d7c671e771b0e109e (patch)
tree2d785cec22226e24ac14bcaa51c4e4c1898b8145 /drivers
parentc3c0d546d73ad53c85789154872b8c92d1f96ba1 (diff)
parent3e26c5feed2add218046ecf91bab3cfa9bf762a6 (diff)
downloadlinux-abf02e2964b3aaf1d5197c5d7c671e771b0e109e.tar.bz2
Merge tag 'pm-5.2-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management fix from Rafael Wysocki: "Prevent PCI bridges in general (and PCIe ports in particular) from being put into low-power states during system-wide suspend transitions if there are any devices in D0 below them and refine the handling of PCI devices in D0 during suspend-to-idle cycles" * tag 'pm-5.2-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: PCI: PM: Skip devices in D0 for suspend-to-idle
Diffstat (limited to 'drivers')
-rw-r--r--drivers/pci/pci-driver.c47
1 files changed, 35 insertions, 12 deletions
diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
index 5eadbc3d0969..98af9ecd4a90 100644
--- a/drivers/pci/pci-driver.c
+++ b/drivers/pci/pci-driver.c
@@ -524,7 +524,6 @@ static void pci_pm_default_resume_early(struct pci_dev *pci_dev)
pci_power_up(pci_dev);
pci_restore_state(pci_dev);
pci_pme_restore(pci_dev);
- pci_fixup_device(pci_fixup_resume_early, pci_dev);
}
/*
@@ -831,18 +830,16 @@ static int pci_pm_suspend_noirq(struct device *dev)
if (pci_dev->skip_bus_pm) {
/*
- * The function is running for the second time in a row without
+ * Either the device is a bridge with a child in D0 below it, or
+ * the function is running for the second time in a row without
* going through full resume, which is possible only during
- * suspend-to-idle in a spurious wakeup case. Moreover, the
- * device was originally left in D0, so its power state should
- * not be changed here and the device register values saved
- * originally should be restored on resume again.
+ * suspend-to-idle in a spurious wakeup case. The device should
+ * be in D0 at this point, but if it is a bridge, it may be
+ * necessary to save its state.
*/
- pci_dev->state_saved = true;
- } else if (pci_dev->state_saved) {
- if (pci_dev->current_state == PCI_D0)
- pci_dev->skip_bus_pm = true;
- } else {
+ if (!pci_dev->state_saved)
+ pci_save_state(pci_dev);
+ } else if (!pci_dev->state_saved) {
pci_save_state(pci_dev);
if (pci_power_manageable(pci_dev))
pci_prepare_to_sleep(pci_dev);
@@ -851,6 +848,22 @@ static int pci_pm_suspend_noirq(struct device *dev)
dev_dbg(dev, "PCI PM: Suspend power state: %s\n",
pci_power_name(pci_dev->current_state));
+ if (pci_dev->current_state == PCI_D0) {
+ pci_dev->skip_bus_pm = true;
+ /*
+ * Per PCI PM r1.2, table 6-1, a bridge must be in D0 if any
+ * downstream device is in D0, so avoid changing the power state
+ * of the parent bridge by setting the skip_bus_pm flag for it.
+ */
+ if (pci_dev->bus->self)
+ pci_dev->bus->self->skip_bus_pm = true;
+ }
+
+ if (pci_dev->skip_bus_pm && !pm_suspend_via_firmware()) {
+ dev_dbg(dev, "PCI PM: Skipped\n");
+ goto Fixup;
+ }
+
pci_pm_set_unknown_state(pci_dev);
/*
@@ -898,7 +911,16 @@ static int pci_pm_resume_noirq(struct device *dev)
if (dev_pm_smart_suspend_and_suspended(dev))
pm_runtime_set_active(dev);
- pci_pm_default_resume_early(pci_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.
+ */
+ if (!pci_dev->skip_bus_pm || pm_suspend_via_firmware())
+ pci_pm_default_resume_early(pci_dev);
+
+ pci_fixup_device(pci_fixup_resume_early, pci_dev);
if (pci_has_legacy_pm_support(pci_dev))
return pci_legacy_resume_early(dev);
@@ -1194,6 +1216,7 @@ static int pci_pm_restore_noirq(struct device *dev)
}
pci_pm_default_resume_early(pci_dev);
+ pci_fixup_device(pci_fixup_resume_early, pci_dev);
if (pci_has_legacy_pm_support(pci_dev))
return pci_legacy_resume_early(dev);