| Message ID | 125862518.pYVN4SKj76@aspire.rjw.lan (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
On Wed, Nov 08, 2017 at 02:28:18PM +0100, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > > Add support for DPM_FLAG_LEAVE_SUSPENDED to the PCI bus type by > making it (a) set the power.may_skip_resume status bit for devices > that, from its perspective, may be left in suspend after system > wakeup from sleep and (b) return early from pci_pm_resume_noirq() > for devices whose remaining resume callbacks during the transition > under way are going to be skipped by the PM core. > > 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> > --- > Documentation/power/pci.txt | 11 +++++++++++ > drivers/pci/pci-driver.c | 19 +++++++++++++++++-- > 2 files changed, 28 insertions(+), 2 deletions(-) > > Index: linux-pm/drivers/pci/pci-driver.c > =================================================================== > --- linux-pm.orig/drivers/pci/pci-driver.c > +++ linux-pm/drivers/pci/pci-driver.c > @@ -699,7 +699,7 @@ static void pci_pm_complete(struct devic > pm_generic_complete(dev); > > /* Resume device if platform firmware has put it in reset-power-on */ > - if (dev->power.direct_complete && pm_resume_via_firmware()) { > + if (pm_runtime_suspended(dev) && pm_resume_via_firmware()) { > pci_power_t pre_sleep_state = pci_dev->current_state; > > pci_update_current_state(pci_dev, pci_dev->current_state); > @@ -783,8 +783,10 @@ static int pci_pm_suspend_noirq(struct d > 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)) > + if (dev_pm_smart_suspend_and_suspended(dev)) { > + dev->power.may_skip_resume = true; > return 0; > + } > > if (pci_has_legacy_pm_support(pci_dev)) > return pci_legacy_suspend_late(dev, PMSG_SUSPEND); > @@ -838,6 +840,16 @@ static int pci_pm_suspend_noirq(struct d > Fixup: > pci_fixup_device(pci_fixup_suspend_late, pci_dev); > > + /* > + * If the target system sleep state is suspend-to-idle, it is sufficient > + * to check whether or not the device's wakeup settings are good for > + * runtime PM. Otherwise, the pm_resume_via_firmware() check will cause > + * pci_pm_complete() to take care of fixing up the device's state > + * anyway, if need be. > + */ > + dev->power.may_skip_resume = device_may_wakeup(dev) || > + !device_can_wakeup(dev); > + > return 0; > } > > @@ -847,6 +859,9 @@ static int pci_pm_resume_noirq(struct de > struct device_driver *drv = dev->driver; > int error = 0; > > + if (dev_pm_may_skip_resume(dev)) > + return 0; > + > /* > * Devices with DPM_FLAG_SMART_SUSPEND may be left in runtime suspend > * during system suspend, so update their runtime PM status to "active" > Index: linux-pm/Documentation/power/pci.txt > =================================================================== > --- linux-pm.orig/Documentation/power/pci.txt > +++ linux-pm/Documentation/power/pci.txt > @@ -994,6 +994,17 @@ into D0 going forward), but if it is in > 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. > > +Setting the DPM_FLAG_LEAVE_SUSPENDED flag means that the driver prefers the > +device to be left in suspend after system-wide transitions to the working state. > +This flag is checked by the PM core, but the PCI bus type informs the PM core > +which devices may be left in suspend from its perspective (that happens during > +the "noirq" phase of system-wide suspend and analogous transitions) and next it > +uses the dev_pm_may_skip_resume() helper to decide whether or not to return from > +pci_pm_resume_noirq() early, as the PM core will skip the remaining resume > +callbacks for the device during the transition under way and will set its > +runtime PM status to "suspended" if dev_pm_may_skip_resume() returns "true" for > +it. > + > 3.2. Device Runtime Power Management > ------------------------------------ > In addition to providing device power management callbacks PCI device drivers > > -- > To unsubscribe from this list: send the line "unsubscribe linux-acpi" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, Nov 8, 2017 at 9:38 PM, Bjorn Helgaas <helgaas@kernel.org> wrote: > On Wed, Nov 08, 2017 at 02:28:18PM +0100, Rafael J. Wysocki wrote: >> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com> >> >> Add support for DPM_FLAG_LEAVE_SUSPENDED to the PCI bus type by >> making it (a) set the power.may_skip_resume status bit for devices >> that, from its perspective, may be left in suspend after system >> wakeup from sleep and (b) return early from pci_pm_resume_noirq() >> for devices whose remaining resume callbacks during the transition >> under way are going to be skipped by the PM core. >> >> 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> Thanks!
Index: linux-pm/drivers/pci/pci-driver.c =================================================================== --- linux-pm.orig/drivers/pci/pci-driver.c +++ linux-pm/drivers/pci/pci-driver.c @@ -699,7 +699,7 @@ static void pci_pm_complete(struct devic pm_generic_complete(dev); /* Resume device if platform firmware has put it in reset-power-on */ - if (dev->power.direct_complete && pm_resume_via_firmware()) { + if (pm_runtime_suspended(dev) && pm_resume_via_firmware()) { pci_power_t pre_sleep_state = pci_dev->current_state; pci_update_current_state(pci_dev, pci_dev->current_state); @@ -783,8 +783,10 @@ static int pci_pm_suspend_noirq(struct d 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)) + if (dev_pm_smart_suspend_and_suspended(dev)) { + dev->power.may_skip_resume = true; return 0; + } if (pci_has_legacy_pm_support(pci_dev)) return pci_legacy_suspend_late(dev, PMSG_SUSPEND); @@ -838,6 +840,16 @@ static int pci_pm_suspend_noirq(struct d Fixup: pci_fixup_device(pci_fixup_suspend_late, pci_dev); + /* + * If the target system sleep state is suspend-to-idle, it is sufficient + * to check whether or not the device's wakeup settings are good for + * runtime PM. Otherwise, the pm_resume_via_firmware() check will cause + * pci_pm_complete() to take care of fixing up the device's state + * anyway, if need be. + */ + dev->power.may_skip_resume = device_may_wakeup(dev) || + !device_can_wakeup(dev); + return 0; } @@ -847,6 +859,9 @@ static int pci_pm_resume_noirq(struct de struct device_driver *drv = dev->driver; int error = 0; + if (dev_pm_may_skip_resume(dev)) + return 0; + /* * Devices with DPM_FLAG_SMART_SUSPEND may be left in runtime suspend * during system suspend, so update their runtime PM status to "active" Index: linux-pm/Documentation/power/pci.txt =================================================================== --- linux-pm.orig/Documentation/power/pci.txt +++ linux-pm/Documentation/power/pci.txt @@ -994,6 +994,17 @@ into D0 going forward), but if it is in 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. +Setting the DPM_FLAG_LEAVE_SUSPENDED flag means that the driver prefers the +device to be left in suspend after system-wide transitions to the working state. +This flag is checked by the PM core, but the PCI bus type informs the PM core +which devices may be left in suspend from its perspective (that happens during +the "noirq" phase of system-wide suspend and analogous transitions) and next it +uses the dev_pm_may_skip_resume() helper to decide whether or not to return from +pci_pm_resume_noirq() early, as the PM core will skip the remaining resume +callbacks for the device during the transition under way and will set its +runtime PM status to "suspended" if dev_pm_may_skip_resume() returns "true" for +it. + 3.2. Device Runtime Power Management ------------------------------------ In addition to providing device power management callbacks PCI device drivers