Commit ee85f543 authored by Huang Ying's avatar Huang Ying Committed by Bjorn Helgaas

ACPI/PM: specify lowest allowed state for device sleep state

Lower device sleep state can save more power, but has more exit
latency too.  Sometimes, to satisfy some power QoS and other
requirement, we need to constrain the lowest device sleep state.

In this patch, a parameter to specify lowest allowed state for
acpi_pm_device_sleep_state is added.  So that the caller can enforce
the constraint via the parameter.

This is needed by PCIe D3cold support, where the lowest power state
allowed may be D3_HOT instead of default D3_COLD.

CC: Len Brown <lenb@kernel.org>
CC: linux-acpi@vger.kernel.org
Reviewed-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: default avatarHuang Ying <ying.huang@intel.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
parent cfaf0251
...@@ -716,8 +716,9 @@ int acpi_suspend(u32 acpi_state) ...@@ -716,8 +716,9 @@ int acpi_suspend(u32 acpi_state)
* @dev: device to examine; its driver model wakeup flags control * @dev: device to examine; its driver model wakeup flags control
* whether it should be able to wake up the system * whether it should be able to wake up the system
* @d_min_p: used to store the upper limit of allowed states range * @d_min_p: used to store the upper limit of allowed states range
* Return value: preferred power state of the device on success, -ENODEV on * @d_max_in: specify the lowest allowed states
* failure (ie. if there's no 'struct acpi_device' for @dev) * Return value: preferred power state of the device on success, -ENODEV
* (ie. if there's no 'struct acpi_device' for @dev) or -EINVAL on failure
* *
* Find the lowest power (highest number) ACPI device power state that * Find the lowest power (highest number) ACPI device power state that
* device @dev can be in while the system is in the sleep state represented * device @dev can be in while the system is in the sleep state represented
...@@ -732,13 +733,15 @@ int acpi_suspend(u32 acpi_state) ...@@ -732,13 +733,15 @@ int acpi_suspend(u32 acpi_state)
* via @wake. * via @wake.
*/ */
int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p) int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p, int d_max_in)
{ {
acpi_handle handle = DEVICE_ACPI_HANDLE(dev); acpi_handle handle = DEVICE_ACPI_HANDLE(dev);
struct acpi_device *adev; struct acpi_device *adev;
char acpi_method[] = "_SxD"; char acpi_method[] = "_SxD";
unsigned long long d_min, d_max; unsigned long long d_min, d_max;
if (d_max_in < ACPI_STATE_D0 || d_max_in > ACPI_STATE_D3)
return -EINVAL;
if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &adev))) { if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &adev))) {
printk(KERN_DEBUG "ACPI handle has no context!\n"); printk(KERN_DEBUG "ACPI handle has no context!\n");
return -ENODEV; return -ENODEV;
...@@ -746,8 +749,10 @@ int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p) ...@@ -746,8 +749,10 @@ int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p)
acpi_method[2] = '0' + acpi_target_sleep_state; acpi_method[2] = '0' + acpi_target_sleep_state;
/* /*
* If the sleep state is S0, we will return D3, but if the device has * If the sleep state is S0, the lowest limit from ACPI is D3,
* _S0W, we will use the value from _S0W * but if the device has _S0W, we will use the value from _S0W
* as the lowest limit from ACPI. Finally, we will constrain
* the lowest limit with the specified one.
*/ */
d_min = ACPI_STATE_D0; d_min = ACPI_STATE_D0;
d_max = ACPI_STATE_D3; d_max = ACPI_STATE_D3;
...@@ -791,8 +796,17 @@ int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p) ...@@ -791,8 +796,17 @@ int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p)
} }
} }
if (d_max_in < d_min)
return -EINVAL;
if (d_min_p) if (d_min_p)
*d_min_p = d_min; *d_min_p = d_min;
/* constrain d_max with specified lowest limit (max number) */
if (d_max > d_max_in) {
for (d_max = d_max_in; d_max > d_min; d_max--) {
if (adev->power.states[d_max].flags.valid)
break;
}
}
return d_max; return d_max;
} }
#endif /* CONFIG_PM */ #endif /* CONFIG_PM */
......
...@@ -189,7 +189,8 @@ static pci_power_t acpi_pci_choose_state(struct pci_dev *pdev) ...@@ -189,7 +189,8 @@ static pci_power_t acpi_pci_choose_state(struct pci_dev *pdev)
{ {
int acpi_state; int acpi_state;
acpi_state = acpi_pm_device_sleep_state(&pdev->dev, NULL); acpi_state = acpi_pm_device_sleep_state(&pdev->dev, NULL,
ACPI_STATE_D3);
if (acpi_state < 0) if (acpi_state < 0)
return PCI_POWER_ERROR; return PCI_POWER_ERROR;
......
...@@ -170,8 +170,8 @@ static int pnpacpi_suspend(struct pnp_dev *dev, pm_message_t state) ...@@ -170,8 +170,8 @@ static int pnpacpi_suspend(struct pnp_dev *dev, pm_message_t state)
} }
if (acpi_bus_power_manageable(handle)) { if (acpi_bus_power_manageable(handle)) {
int power_state = acpi_pm_device_sleep_state(&dev->dev, NULL); int power_state = acpi_pm_device_sleep_state(&dev->dev, NULL,
ACPI_STATE_D3);
if (power_state < 0) if (power_state < 0)
power_state = (state.event == PM_EVENT_ON) ? power_state = (state.event == PM_EVENT_ON) ?
ACPI_STATE_D0 : ACPI_STATE_D3; ACPI_STATE_D0 : ACPI_STATE_D3;
......
...@@ -414,13 +414,13 @@ int acpi_enable_wakeup_device_power(struct acpi_device *dev, int state); ...@@ -414,13 +414,13 @@ int acpi_enable_wakeup_device_power(struct acpi_device *dev, int state);
int acpi_disable_wakeup_device_power(struct acpi_device *dev); int acpi_disable_wakeup_device_power(struct acpi_device *dev);
#ifdef CONFIG_PM #ifdef CONFIG_PM
int acpi_pm_device_sleep_state(struct device *, int *); int acpi_pm_device_sleep_state(struct device *, int *, int);
#else #else
static inline int acpi_pm_device_sleep_state(struct device *d, int *p) static inline int acpi_pm_device_sleep_state(struct device *d, int *p, int m)
{ {
if (p) if (p)
*p = ACPI_STATE_D0; *p = ACPI_STATE_D0;
return ACPI_STATE_D3; return (m >= ACPI_STATE_D0 && m <= ACPI_STATE_D3) ? m : ACPI_STATE_D0;
} }
#endif #endif
......
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