diff options
Diffstat (limited to 'drivers/pci/pci-driver.c')
| -rw-r--r-- | drivers/pci/pci-driver.c | 47 |
1 files changed, 35 insertions, 12 deletions
diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index dd656cf19a12..bd097ea5925c 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); } /* @@ -842,18 +841,16 @@ 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); @@ -862,6 +859,22 @@ 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); /* @@ -909,7 +922,16 @@ 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); @@ -1208,6 +1230,7 @@ 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); |