Re: [PATCH 7/7] PM / ACPI: Take device PM QoS flags into account

mark gross
2012-10-10T03:36:27Z

On Mon, Oct 08, 2012 at 10:09:26AM +0200, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
>
> 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 <rafael.j.wysocki@intel.com>
> Reviewed-by: Jean Pihet <j-pihet@ti.com>
> ---
> drivers/acpi/sleep.c | 21 +++++++++++++++++----
> drivers/pci/pci-acpi.c | 8 +++++++-
> 2 files changed, 24 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 +720,13 @@ int acpi_pm_device_sleep_state(struct de
> printk(KERN_DEBUG "ACPI handle has no context!\n");
> return -ENODEV;
> }
> + if (d_max_in > ACPI_STATE_D3_HOT) {
> + enum pm_qos_flags_status stat;
> +
> + stat = dev_pm_qos_flags(dev, PM_QOS_FLAG_NO_POWER_OFF);
> + if (stat == PM_QOS_FLAGS_ALL)
> + d_max_in = ACPI_STATE_D3_HOT;
> + }
>
> acpi_method[2] = '0' + acpi_target_sleep_state;
> /*
> @@ -737,8 +746,14 @@ int acpi_pm_device_sleep_state(struct de
> * NOTE: We rely on acpi_evaluate_integer() not clobbering the integer
> * provided -- that's our fault recovery, we ignore retval.
> */
> - if (acpi_target_sleep_state > ACPI_STATE_S0)
> + if (acpi_target_sleep_state > ACPI_STATE_S0) {
> acpi_evaluate_integer(handle, acpi_method, NULL, &d_min);
> + wakeup = device_may_wakeup(dev) && adev->wakeup.flags.valid
> + && adev->wakeup.sleep_state >= acpi_target_sleep_state;
> + } else if (dev_pm_qos_flags(dev, PM_QOS_FLAG_REMOTE_WAKEUP) !=
> + PM_QOS_FLAGS_NONE) {
> + wakeup = adev->wakeup.flags.valid;
> + }
>
> /*
> * If _PRW says we can wake up the system from the target sleep state,
> @@ -747,9 +762,7 @@ int acpi_pm_device_sleep_state(struct de
> * (ACPI 3.x), it should return the maximum (lowest power) D-state that
> * can wake the system. _S0W may be valid, too.
> */
> - if (acpi_target_sleep_state == ACPI_STATE_S0 ||
> - (device_may_wakeup(dev) && adev->wakeup.flags.valid &&
> - adev->wakeup.sleep_state >= acpi_target_sleep_state)) {
> + if (wakeup) {
> acpi_status status;
>
> acpi_method[3] = 'W';
>
> --
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> Reviewed-by: mark gross <markgross@thegnar.org>