From 08810a4119aaebf6318f209ec5dd9828e969cba4 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Wed, 25 Oct 2017 14:12:29 +0200 Subject: PM / core: Add NEVER_SKIP and SMART_PREPARE driver flags The motivation for this change is to provide a way to work around a problem with the direct-complete mechanism used for avoiding system suspend/resume handling for devices in runtime suspend. The problem is that some middle layer code (the PCI bus type and the ACPI PM domain in particular) returns positive values from its system suspend ->prepare callbacks regardless of whether the driver's ->prepare returns a positive value or 0, which effectively prevents drivers from being able to control the direct-complete feature. Some drivers need that control, however, and the PCI bus type has grown its own flag to deal with this issue, but since it is not limited to PCI, it is better to address it by adding driver flags at the core level. To that end, add a driver_flags field to struct dev_pm_info for flags that can be set by device drivers at the probe time to inform the PM core and/or bus types, PM domains and so on on the capabilities and/or preferences of device drivers. Also add two static inline helpers for setting that field and testing it against a given set of flags and make the driver core clear it automatically on driver remove and probe failures. Define and document two PM driver flags related to the direct- complete feature: NEVER_SKIP and SMART_PREPARE that can be used, respectively, to indicate to the PM core that the direct-complete mechanism should never be used for the device and to inform the middle layer code (bus types, PM domains etc) that it can only request the PM core to use the direct-complete mechanism for the device (by returning a positive value from its ->prepare callback) if it also has been requested by the driver. While at it, make the core check pm_runtime_suspended() when setting power.direct_complete so that it doesn't need to be checked by ->prepare callbacks. Signed-off-by: Rafael J. Wysocki Acked-by: Greg Kroah-Hartman Acked-by: Bjorn Helgaas Reviewed-by: Ulf Hansson --- drivers/pci/pci-driver.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'drivers/pci') diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index 11bd267fc137..68a32703b30a 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -689,8 +689,11 @@ static int pci_pm_prepare(struct device *dev) if (drv && drv->pm && drv->pm->prepare) { int error = drv->pm->prepare(dev); - if (error) + if (error < 0) return error; + + if (!error && dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_PREPARE)) + return 0; } return pci_dev_keep_suspended(to_pci_dev(dev)); } -- cgit v1.2.3 From c2eac4d3a115e2f511844e7bcf73f4e877fbf5da Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Wed, 25 Oct 2017 14:16:46 +0200 Subject: PCI / PM: Use the NEVER_SKIP driver flag Replace the PCI-specific flag PCI_DEV_FLAGS_NEEDS_RESUME with the PM core's DPM_FLAG_NEVER_SKIP one everywhere and drop it. Signed-off-by: Rafael J. Wysocki Acked-by: Greg Kroah-Hartman Acked-by: Bjorn Helgaas Reviewed-by: Ulf Hansson --- drivers/pci/pci.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'drivers/pci') diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 6078dfc11b11..374f5686e2bc 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -2166,8 +2166,7 @@ bool pci_dev_keep_suspended(struct pci_dev *pci_dev) if (!pm_runtime_suspended(dev) || pci_target_state(pci_dev, wakeup) != pci_dev->current_state - || platform_pci_need_resume(pci_dev) - || (pci_dev->dev_flags & PCI_DEV_FLAGS_NEEDS_RESUME)) + || platform_pci_need_resume(pci_dev)) return false; /* -- cgit v1.2.3 From 302666d8a55ce7eb5fb0bd9fbd9437d74e0ce77c Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Thu, 26 Oct 2017 12:12:16 +0200 Subject: PCI / PM: Drop unnecessary invocations of pcibios_pm_ops callbacks The only user of non-empty pcibios_pm_ops is s390 and it only uses "noirq" callbacks, so drop the invocations of the other pcibios_pm_ops callbacks from the PCI PM code. That will allow subsequent changes to be somewhat simpler. Signed-off-by: Rafael J. Wysocki Acked-by: Greg Kroah-Hartman Acked-by: Bjorn Helgaas Reviewed-by: Ulf Hansson --- drivers/pci/pci-driver.c | 18 ------------------ 1 file changed, 18 deletions(-) (limited to 'drivers/pci') diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index 68a32703b30a..c1aeeb10539e 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -922,9 +922,6 @@ static int pci_pm_freeze(struct device *dev) return error; } - if (pcibios_pm_ops.freeze) - return pcibios_pm_ops.freeze(dev); - return 0; } @@ -986,12 +983,6 @@ static int pci_pm_thaw(struct device *dev) const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; int error = 0; - if (pcibios_pm_ops.thaw) { - error = pcibios_pm_ops.thaw(dev); - if (error) - return error; - } - if (pci_has_legacy_pm_support(pci_dev)) return pci_legacy_resume(dev); @@ -1036,9 +1027,6 @@ static int pci_pm_poweroff(struct device *dev) Fixup: pci_fixup_device(pci_fixup_suspend, pci_dev); - if (pcibios_pm_ops.poweroff) - return pcibios_pm_ops.poweroff(dev); - return 0; } @@ -1111,12 +1099,6 @@ static int pci_pm_restore(struct device *dev) const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; int error = 0; - if (pcibios_pm_ops.restore) { - error = pcibios_pm_ops.restore(dev); - if (error) - return error; - } - /* * This is necessary for the hibernation error path in which restore is * called without restoring the standard config registers of the device. -- cgit v1.2.3 From c4b65157aeefad29b2351a00a010e8c40ce7fd0e Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Thu, 26 Oct 2017 12:12:22 +0200 Subject: PCI / PM: Take SMART_SUSPEND driver flag into account Make the PCI bus type take DPM_FLAG_SMART_SUSPEND into account in its system-wide PM callbacks and make sure that all code that should not run in parallel with pci_pm_runtime_resume() is executed in the "late" phases of system suspend, freeze and poweroff transitions. [Note that the pm_runtime_suspended() check in pci_dev_keep_suspended() is an optimization, because if is not passed, all of the subsequent checks may be skipped and some of them are much more overhead in general.] Also use the observation that if the device is in runtime suspend at the beginning of the "late" phase of a system-wide suspend-like transition, its state cannot change going forward (runtime PM is disabled for it at that time) until the transition is over and the subsequent system-wide PM callbacks should be skipped for it (as they generally assume the device to not be suspended), so add checks for that in pci_pm_suspend_late/noirq(), pci_pm_freeze_late/noirq() and pci_pm_poweroff_late/noirq(). Moreover, if pci_pm_resume_noirq() or pci_pm_restore_noirq() is called during the subsequent system-wide resume transition and if the device was left in runtime suspend previously, its runtime PM status needs to be changed to "active" as it is going to be put into the full-power state, so add checks for that too to these functions. In turn, if pci_pm_thaw_noirq() runs after the device has been left in runtime suspend, the subsequent "thaw" callbacks need to be skipped for it (as they may not work correctly with a suspended device), so set the power.direct_complete flag for the device then to make the PM core skip those callbacks. In addition to the above add a core helper for checking if DPM_FLAG_SMART_SUSPEND is set and the device runtime PM status is "suspended" at the same time, which is done quite often in the new code (and will be done elsewhere going forward too). Signed-off-by: Rafael J. Wysocki Acked-by: Greg Kroah-Hartman Acked-by: Bjorn Helgaas --- drivers/pci/pci-driver.c | 103 +++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 86 insertions(+), 17 deletions(-) (limited to 'drivers/pci') diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index c1aeeb10539e..d19bd54d337e 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -734,18 +734,25 @@ static int pci_pm_suspend(struct device *dev) if (!pm) { pci_pm_default_suspend(pci_dev); - goto Fixup; + return 0; } /* - * PCI devices suspended at run time need to be resumed at this point, - * because in general it is necessary to reconfigure them for system - * suspend. Namely, if the device is supposed to wake up the system - * from the sleep state, we may need to reconfigure it for this purpose. - * In turn, if the device is not supposed to wake up the system from the - * sleep state, we'll have to prevent it from signaling wake-up. + * PCI devices suspended at run time may need to be resumed at this + * point, because in general it may be necessary to reconfigure them for + * system suspend. Namely, if the device is expected to wake up the + * system from the sleep state, it may have to be reconfigured for this + * purpose, or if the device is not expected to wake up the system from + * the sleep state, it should be prevented from signaling wakeup events + * going forward. + * + * Also if the driver of the device does not indicate that its system + * suspend callbacks can cope with runtime-suspended devices, it is + * better to resume the device from runtime suspend here. */ - pm_runtime_resume(dev); + if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) || + !pci_dev_keep_suspended(pci_dev)) + pm_runtime_resume(dev); pci_dev->state_saved = false; if (pm->suspend) { @@ -765,17 +772,27 @@ static int pci_pm_suspend(struct device *dev) } } - Fixup: - pci_fixup_device(pci_fixup_suspend, pci_dev); - return 0; } +static int pci_pm_suspend_late(struct device *dev) +{ + if (dev_pm_smart_suspend_and_suspended(dev)) + return 0; + + pci_fixup_device(pci_fixup_suspend, to_pci_dev(dev)); + + return pm_generic_suspend_late(dev); +} + static int pci_pm_suspend_noirq(struct device *dev) { struct pci_dev *pci_dev = to_pci_dev(dev); const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; + if (dev_pm_smart_suspend_and_suspended(dev)) + return 0; + if (pci_has_legacy_pm_support(pci_dev)) return pci_legacy_suspend_late(dev, PMSG_SUSPEND); @@ -834,6 +851,14 @@ static int pci_pm_resume_noirq(struct device *dev) struct device_driver *drv = dev->driver; int error = 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); + pci_pm_default_resume_early(pci_dev); if (pci_has_legacy_pm_support(pci_dev)) @@ -876,6 +901,7 @@ static int pci_pm_resume(struct device *dev) #else /* !CONFIG_SUSPEND */ #define pci_pm_suspend NULL +#define pci_pm_suspend_late NULL #define pci_pm_suspend_noirq NULL #define pci_pm_resume NULL #define pci_pm_resume_noirq NULL @@ -910,7 +936,8 @@ static int pci_pm_freeze(struct device *dev) * devices should not be touched during freeze/thaw transitions, * however. */ - pm_runtime_resume(dev); + if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND)) + pm_runtime_resume(dev); pci_dev->state_saved = false; if (pm->freeze) { @@ -925,11 +952,22 @@ static int pci_pm_freeze(struct device *dev) return 0; } +static int pci_pm_freeze_late(struct device *dev) +{ + if (dev_pm_smart_suspend_and_suspended(dev)) + return 0; + + return pm_generic_freeze_late(dev);; +} + static int pci_pm_freeze_noirq(struct device *dev) { struct pci_dev *pci_dev = to_pci_dev(dev); struct device_driver *drv = dev->driver; + if (dev_pm_smart_suspend_and_suspended(dev)) + return 0; + if (pci_has_legacy_pm_support(pci_dev)) return pci_legacy_suspend_late(dev, PMSG_FREEZE); @@ -959,6 +997,16 @@ static int pci_pm_thaw_noirq(struct device *dev) struct device_driver *drv = dev->driver; int error = 0; + /* + * If the device is in runtime suspend, the code below may not work + * correctly with it, so skip that code and make the PM core skip all of + * the subsequent "thaw" callbacks for the device. + */ + if (dev_pm_smart_suspend_and_suspended(dev)) { + dev->power.direct_complete = true; + return 0; + } + if (pcibios_pm_ops.thaw_noirq) { error = pcibios_pm_ops.thaw_noirq(dev); if (error) @@ -1008,11 +1056,13 @@ static int pci_pm_poweroff(struct device *dev) if (!pm) { pci_pm_default_suspend(pci_dev); - goto Fixup; + return 0; } /* The reason to do that is the same as in pci_pm_suspend(). */ - pm_runtime_resume(dev); + if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) || + !pci_dev_keep_suspended(pci_dev)) + pm_runtime_resume(dev); pci_dev->state_saved = false; if (pm->poweroff) { @@ -1024,17 +1074,27 @@ static int pci_pm_poweroff(struct device *dev) return error; } - Fixup: - pci_fixup_device(pci_fixup_suspend, pci_dev); - return 0; } +static int pci_pm_poweroff_late(struct device *dev) +{ + if (dev_pm_smart_suspend_and_suspended(dev)) + return 0; + + pci_fixup_device(pci_fixup_suspend, to_pci_dev(dev)); + + return pm_generic_poweroff_late(dev); +} + static int pci_pm_poweroff_noirq(struct device *dev) { struct pci_dev *pci_dev = to_pci_dev(dev); struct device_driver *drv = dev->driver; + if (dev_pm_smart_suspend_and_suspended(dev)) + return 0; + if (pci_has_legacy_pm_support(to_pci_dev(dev))) return pci_legacy_suspend_late(dev, PMSG_HIBERNATE); @@ -1076,6 +1136,10 @@ static int pci_pm_restore_noirq(struct device *dev) struct device_driver *drv = dev->driver; int error = 0; + /* This is analogous to the pci_pm_resume_noirq() case. */ + if (dev_pm_smart_suspend_and_suspended(dev)) + pm_runtime_set_active(dev); + if (pcibios_pm_ops.restore_noirq) { error = pcibios_pm_ops.restore_noirq(dev); if (error) @@ -1124,10 +1188,12 @@ static int pci_pm_restore(struct device *dev) #else /* !CONFIG_HIBERNATE_CALLBACKS */ #define pci_pm_freeze NULL +#define pci_pm_freeze_late NULL #define pci_pm_freeze_noirq NULL #define pci_pm_thaw NULL #define pci_pm_thaw_noirq NULL #define pci_pm_poweroff NULL +#define pci_pm_poweroff_late NULL #define pci_pm_poweroff_noirq NULL #define pci_pm_restore NULL #define pci_pm_restore_noirq NULL @@ -1243,10 +1309,13 @@ static const struct dev_pm_ops pci_dev_pm_ops = { .prepare = pci_pm_prepare, .complete = pci_pm_complete, .suspend = pci_pm_suspend, + .suspend_late = pci_pm_suspend_late, .resume = pci_pm_resume, .freeze = pci_pm_freeze, + .freeze_late = pci_pm_freeze_late, .thaw = pci_pm_thaw, .poweroff = pci_pm_poweroff, + .poweroff_late = pci_pm_poweroff_late, .restore = pci_pm_restore, .suspend_noirq = pci_pm_suspend_noirq, .resume_noirq = pci_pm_resume_noirq, -- cgit v1.2.3