On Saturday, September 29, 2012, Huang Ying wrote:
> On Fri, 2012-09-28 at 23:56 +0200, Rafael J. Wysocki wrote:
> > Make ACPI power management routines and PCI power management
> > routines depending on ACPI take device PM QoS flags into account
> > when deciding what power state to put the device into.
> >
> > In particular, after this change acpi_pm_device_sleep_state() will
> > not return ACPI_STATE_D3_COLD as the deepest available low-power
> > state if PM_QOS_FLAG_NO_POWER_OFF is requested for the device and it
> > will not require remote wakeup to work for the device in the returned
> > low-power state if there is at least one PM QoS flags request for the
> > device, but PM_QOS_FLAG_REMOTE_WAKEUP is not requested for it.
> >
> > Accordingly, acpi_pci_set_power_state() will refuse to put the
> > device into D3cold if PM_QOS_FLAG_NO_POWER_OFF is requested for it.
> >
> > Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx>
> > ---
> > drivers/acpi/sleep.c | 16 ++++++++++++----
> > drivers/pci/pci-acpi.c | 8 +++++++-
> > 2 files changed, 19 insertions(+), 5 deletions(-)
> >
> > Index: linux/drivers/pci/pci-acpi.c
> > ===================================================================
> > --- linux.orig/drivers/pci/pci-acpi.c
> > +++ linux/drivers/pci/pci-acpi.c
> > @@ -17,6 +17,7 @@
> >
> > #include <linux/pci-acpi.h>
> > #include <linux/pm_runtime.h>
> > +#include <linux/pm_qos.h>
> > #include "pci.h"
> >
> > static DEFINE_MUTEX(pci_acpi_pm_notify_mtx);
> > @@ -257,11 +258,16 @@ static int acpi_pci_set_power_state(stru
> > return -ENODEV;
> >
> > switch (state) {
> > + case PCI_D3cold:
> > + if (dev_pm_qos_flags(&dev->dev, PM_QOS_FLAG_NO_POWER_OFF) ==
> > + PM_QOS_FLAGS_ALL) {
> > + error = -EBUSY;
> > + break;
> > + }
> > case PCI_D0:
> > case PCI_D1:
> > case PCI_D2:
> > case PCI_D3hot:
> > - case PCI_D3cold:
> > error = acpi_bus_set_power(handle, state_conv[state]);
> > }
> >
> > Index: linux/drivers/acpi/sleep.c
> > ===================================================================
> > --- linux.orig/drivers/acpi/sleep.c
> > +++ linux/drivers/acpi/sleep.c
> > @@ -19,6 +19,7 @@
> > #include <linux/acpi.h>
> > #include <linux/module.h>
> > #include <linux/pm_runtime.h>
> > +#include <linux/pm_qos.h>
> >
> > #include <asm/io.h>
> >
> > @@ -711,6 +712,7 @@ int acpi_pm_device_sleep_state(struct de
> > struct acpi_device *adev;
> > char acpi_method[] = "_SxD";
> > unsigned long long d_min, d_max;
> > + bool wakeup = false;
> >
> > if (d_max_in < ACPI_STATE_D0 || d_max_in > ACPI_STATE_D3)
> > return -EINVAL;
> > @@ -718,6 +720,8 @@ int acpi_pm_device_sleep_state(struct de
> > printk(KERN_DEBUG "ACPI handle has no context!\n");
> > return -ENODEV;
> > }
> > + if (dev_pm_qos_flags(dev, PM_QOS_FLAG_NO_POWER_OFF) == PM_QOS_FLAGS_ALL)
> > + d_max_in = ACPI_STATE_D3_HOT;
>
> In theory, d_max_in may < ACPI_STATE_D3_HOT.
Good catch!
> So better to be
>
> d_max_in = min_t(int, d_max_in, ACPI_STATE_D3_HOT);
In fact, we don't even need to check the PM QoS flags if d_max_in is not D3_COLD.
> But in fact, d_max_in is introduced to support something similar to
> PM_QOS_FLAG_NO_POWER_OFF, so I think we can remove d_max_in in the
> future.
We probably can, but for now I'll fix the patch.
Thanks,
Rafael
--
To unsubscribe from this list: send the line "unsubscribe linux-pci" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
