| Message ID | 20130204115612.5569.49895.stgit@zurg (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
On Monday, February 04, 2013 03:56:12 PM Konstantin Khlebnikov wrote: > Documentation/power/pci.txt says: > | It is expected that the device driver's pm->runtime_suspend() callback will > | not attempt to prepare the device for signaling wakeup or to put it into a > | low-power state. The driver ought to leave these tasks to the PCI subsystem > | that has all of the information necessary to perform them. > > After commit 42eca2302146fed51335b95128e949ee6f54478f > ("PCI: Don't touch card regs after runtime suspend D3") > | If the driver takes care of state saving, don't touch any registers on it. > pci_pm_runtime_suspend() thinks if state has been saved by ->runtime_suspend() > that means device alredy prepared for wakeup and probably no longer accessible. > > Thus driver must either do all actions or leave all these tasks to PCI subsystem. I don't like this one, because it will generate noise for drivers that legitimately use pci_save_state() in their runtime suspend callbacks and know what they are doing. Thanks, Rafael > Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> > Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > Cc: Bjorn Helgaas <bhelgaas@google.com> > Cc: linux-pci@vger.kernel.org > --- > drivers/pci/pci-driver.c | 15 +++++++++++---- > 1 file changed, 11 insertions(+), 4 deletions(-) > > diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c > index f9aa311..2b0ff9a 100644 > --- a/drivers/pci/pci-driver.c > +++ b/drivers/pci/pci-driver.c > @@ -1009,12 +1009,19 @@ static int pci_pm_runtime_suspend(struct device *dev) > return 0; > } > > - if (!pci_dev->state_saved) { > - pci_save_state(pci_dev); > - pci_finish_runtime_suspend(pci_dev); > + if (pci_dev->state_saved) { > + WARN_ONCE(pci_dev->current_state == prev, > + "PCI PM: Power state of device not changed by %pF\n", > + pm->runtime_suspend); > + WARN_ONCE(pci_dev_run_wake(pci_dev) && > + !pci_dev->wakeup_prepared, > + "PCI PM: Waking of device not configured by %pF\n", > + pm->runtime_suspend); > + return 0; > } > > - return 0; > + pci_save_state(pci_dev); > + return pci_finish_runtime_suspend(pci_dev); > } > > static int pci_pm_runtime_resume(struct device *dev) > > -- > To unsubscribe from this list: send the line "unsubscribe linux-pci" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html
Rafael J. Wysocki wrote: > On Monday, February 04, 2013 03:56:12 PM Konstantin Khlebnikov wrote: >> Documentation/power/pci.txt says: >> | It is expected that the device driver's pm->runtime_suspend() callback will >> | not attempt to prepare the device for signaling wakeup or to put it into a >> | low-power state. The driver ought to leave these tasks to the PCI subsystem >> | that has all of the information necessary to perform them. >> >> After commit 42eca2302146fed51335b95128e949ee6f54478f >> ("PCI: Don't touch card regs after runtime suspend D3") >> | If the driver takes care of state saving, don't touch any registers on it. >> pci_pm_runtime_suspend() thinks if state has been saved by ->runtime_suspend() >> that means device alredy prepared for wakeup and probably no longer accessible. >> >> Thus driver must either do all actions or leave all these tasks to PCI subsystem. > > I don't like this one, because it will generate noise for drivers that > legitimately use pci_save_state() in their runtime suspend callbacks > and know what they are doing. Ok, you're right. Both these warnings can be false-positive. For example some of wifi cards easily might be weird enough for this. > > Thanks, > Rafael > > >> Signed-off-by: Konstantin Khlebnikov<khlebnikov@openvz.org> >> Cc: Rafael J. Wysocki<rafael.j.wysocki@intel.com> >> Cc: Bjorn Helgaas<bhelgaas@google.com> >> Cc: linux-pci@vger.kernel.org >> --- >> drivers/pci/pci-driver.c | 15 +++++++++++---- >> 1 file changed, 11 insertions(+), 4 deletions(-) >> >> diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c >> index f9aa311..2b0ff9a 100644 >> --- a/drivers/pci/pci-driver.c >> +++ b/drivers/pci/pci-driver.c >> @@ -1009,12 +1009,19 @@ static int pci_pm_runtime_suspend(struct device *dev) >> return 0; >> } >> >> - if (!pci_dev->state_saved) { >> - pci_save_state(pci_dev); >> - pci_finish_runtime_suspend(pci_dev); >> + if (pci_dev->state_saved) { >> + WARN_ONCE(pci_dev->current_state == prev, >> + "PCI PM: Power state of device not changed by %pF\n", >> + pm->runtime_suspend); >> + WARN_ONCE(pci_dev_run_wake(pci_dev)&& >> + !pci_dev->wakeup_prepared, >> + "PCI PM: Waking of device not configured by %pF\n", >> + pm->runtime_suspend); >> + return 0; >> } >> >> - return 0; >> + pci_save_state(pci_dev); >> + return pci_finish_runtime_suspend(pci_dev); >> } >> >> static int pci_pm_runtime_resume(struct device *dev) >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-pci" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index f9aa311..2b0ff9a 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -1009,12 +1009,19 @@ static int pci_pm_runtime_suspend(struct device *dev) return 0; } - if (!pci_dev->state_saved) { - pci_save_state(pci_dev); - pci_finish_runtime_suspend(pci_dev); + if (pci_dev->state_saved) { + WARN_ONCE(pci_dev->current_state == prev, + "PCI PM: Power state of device not changed by %pF\n", + pm->runtime_suspend); + WARN_ONCE(pci_dev_run_wake(pci_dev) && + !pci_dev->wakeup_prepared, + "PCI PM: Waking of device not configured by %pF\n", + pm->runtime_suspend); + return 0; } - return 0; + pci_save_state(pci_dev); + return pci_finish_runtime_suspend(pci_dev); } static int pci_pm_runtime_resume(struct device *dev)
Documentation/power/pci.txt says: | It is expected that the device driver's pm->runtime_suspend() callback will | not attempt to prepare the device for signaling wakeup or to put it into a | low-power state. The driver ought to leave these tasks to the PCI subsystem | that has all of the information necessary to perform them. After commit 42eca2302146fed51335b95128e949ee6f54478f ("PCI: Don't touch card regs after runtime suspend D3") | If the driver takes care of state saving, don't touch any registers on it. pci_pm_runtime_suspend() thinks if state has been saved by ->runtime_suspend() that means device alredy prepared for wakeup and probably no longer accessible. Thus driver must either do all actions or leave all these tasks to PCI subsystem. Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: linux-pci@vger.kernel.org --- drivers/pci/pci-driver.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html