| Message ID | 1786526.OJccb5RI6R@aspire.rjw.lan (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
On Sat, Oct 28, 2017 at 12:27:45AM +0200, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > > 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 <rafael.j.wysocki@intel.com> > Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Bjorn Helgaas <bhelgaas@google.com> > --- > > -> v2: Implement the entire handling of DPM_FLAG_SMART_SUSPEND in > the PCI bus type (instead of doing that in the core). > > --- > Documentation/power/pci.txt | 14 +++++ > drivers/base/power/main.c | 6 ++ > drivers/pci/pci-driver.c | 103 ++++++++++++++++++++++++++++++++++++-------- > include/linux/pm.h | 2 > 4 files changed, 108 insertions(+), 17 deletions(-) > > Index: linux-pm/drivers/pci/pci-driver.c > =================================================================== > --- linux-pm.orig/drivers/pci/pci-driver.c > +++ linux-pm/drivers/pci/pci-driver.c > @@ -734,18 +734,25 @@ static int pci_pm_suspend(struct device > > 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 > } > } > > - 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 de > 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 * > #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 * > * 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 * > 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 devi > 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 > > 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 > 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 d > 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 > #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_p > .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, > Index: linux-pm/Documentation/power/pci.txt > =================================================================== > --- linux-pm.orig/Documentation/power/pci.txt > +++ linux-pm/Documentation/power/pci.txt > @@ -980,6 +980,20 @@ positive value from pci_pm_prepare() if > driver of the device returns a positive value. That allows the driver to opt > out from using the direct-complete mechanism dynamically. > > +The DPM_FLAG_SMART_SUSPEND flag tells the PCI bus type that from the driver's > +perspective the device can be safely left in runtime suspend during system > +suspend. That causes pci_pm_suspend(), pci_pm_freeze() and pci_pm_poweroff() > +to skip resuming the device from runtime suspend unless there are PCI-specific > +reasons for doing that. Also, it causes pci_pm_suspend_late/noirq(), > +pci_pm_freeze_late/noirq() and pci_pm_poweroff_late/noirq() to return early > +if the device remains in runtime suspend in the beginning of the "late" phase > +of the system-wide transition under way. Moreover, if the device is in > +runtime suspend in pci_pm_resume_noirq() or pci_pm_restore_noirq(), its runtime > +power management status will be changed to "active" (as it is going to be put > +into D0 going forward), but if it is in runtime suspend in pci_pm_thaw_noirq(), > +the function will set the power.direct_complete flag for it (to make the PM core > +skip the subsequent "thaw" callbacks for it) and return. > + > 3.2. Device Runtime Power Management > ------------------------------------ > In addition to providing device power management callbacks PCI device drivers > Index: linux-pm/drivers/base/power/main.c > =================================================================== > --- linux-pm.orig/drivers/base/power/main.c > +++ linux-pm/drivers/base/power/main.c > @@ -1861,3 +1861,9 @@ void device_pm_check_callbacks(struct de > !dev->driver->suspend && !dev->driver->resume)); > spin_unlock_irq(&dev->power.lock); > } > + > +bool dev_pm_smart_suspend_and_suspended(struct device *dev) > +{ > + return dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) && > + pm_runtime_status_suspended(dev); > +} > Index: linux-pm/include/linux/pm.h > =================================================================== > --- linux-pm.orig/include/linux/pm.h > +++ linux-pm/include/linux/pm.h > @@ -765,6 +765,8 @@ extern int pm_generic_poweroff_late(stru > extern int pm_generic_poweroff(struct device *dev); > extern void pm_generic_complete(struct device *dev); > > +extern bool dev_pm_smart_suspend_and_suspended(struct device *dev); > + > #else /* !CONFIG_PM_SLEEP */ > > #define device_pm_lock() do {} while (0) > >
Index: linux-pm/drivers/pci/pci-driver.c =================================================================== --- linux-pm.orig/drivers/pci/pci-driver.c +++ linux-pm/drivers/pci/pci-driver.c @@ -734,18 +734,25 @@ static int pci_pm_suspend(struct device 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 } } - 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 de 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 * #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 * * 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 * 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 devi 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 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 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 d 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 #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_p .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, Index: linux-pm/Documentation/power/pci.txt =================================================================== --- linux-pm.orig/Documentation/power/pci.txt +++ linux-pm/Documentation/power/pci.txt @@ -980,6 +980,20 @@ positive value from pci_pm_prepare() if driver of the device returns a positive value. That allows the driver to opt out from using the direct-complete mechanism dynamically. +The DPM_FLAG_SMART_SUSPEND flag tells the PCI bus type that from the driver's +perspective the device can be safely left in runtime suspend during system +suspend. That causes pci_pm_suspend(), pci_pm_freeze() and pci_pm_poweroff() +to skip resuming the device from runtime suspend unless there are PCI-specific +reasons for doing that. Also, it causes pci_pm_suspend_late/noirq(), +pci_pm_freeze_late/noirq() and pci_pm_poweroff_late/noirq() to return early +if the device remains in runtime suspend in the beginning of the "late" phase +of the system-wide transition under way. Moreover, if the device is in +runtime suspend in pci_pm_resume_noirq() or pci_pm_restore_noirq(), its runtime +power management status will be changed to "active" (as it is going to be put +into D0 going forward), but if it is in runtime suspend in pci_pm_thaw_noirq(), +the function will set the power.direct_complete flag for it (to make the PM core +skip the subsequent "thaw" callbacks for it) and return. + 3.2. Device Runtime Power Management ------------------------------------ In addition to providing device power management callbacks PCI device drivers Index: linux-pm/drivers/base/power/main.c =================================================================== --- linux-pm.orig/drivers/base/power/main.c +++ linux-pm/drivers/base/power/main.c @@ -1861,3 +1861,9 @@ void device_pm_check_callbacks(struct de !dev->driver->suspend && !dev->driver->resume)); spin_unlock_irq(&dev->power.lock); } + +bool dev_pm_smart_suspend_and_suspended(struct device *dev) +{ + return dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) && + pm_runtime_status_suspended(dev); +} Index: linux-pm/include/linux/pm.h =================================================================== --- linux-pm.orig/include/linux/pm.h +++ linux-pm/include/linux/pm.h @@ -765,6 +765,8 @@ extern int pm_generic_poweroff_late(stru extern int pm_generic_poweroff(struct device *dev); extern void pm_generic_complete(struct device *dev); +extern bool dev_pm_smart_suspend_and_suspended(struct device *dev); + #else /* !CONFIG_PM_SLEEP */ #define device_pm_lock() do {} while (0)