diff options
Diffstat (limited to 'drivers/acpi/device_pm.c')
| -rw-r--r-- | drivers/acpi/device_pm.c | 99 |
1 files changed, 59 insertions, 40 deletions
diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c index 8217e0bda..88dbbb115 100644 --- a/drivers/acpi/device_pm.c +++ b/drivers/acpi/device_pm.c @@ -98,17 +98,16 @@ int acpi_device_get_power(struct acpi_device *device, int *state) /* * The power resources settings may indicate a power state - * shallower than the actual power state of the device. + * shallower than the actual power state of the device, because + * the same power resources may be referenced by other devices. * - * Moreover, on systems predating ACPI 4.0, if the device - * doesn't depend on any power resources and _PSC returns 3, - * that means "power off". We need to maintain compatibility - * with those systems. + * For systems predating ACPI 4.0 we assume that D3hot is the + * deepest state that can be supported. */ if (psc > result && psc < ACPI_STATE_D3_COLD) result = psc; else if (result == ACPI_STATE_UNKNOWN) - result = psc > ACPI_STATE_D2 ? ACPI_STATE_D3_COLD : psc; + result = psc > ACPI_STATE_D2 ? ACPI_STATE_D3_HOT : psc; } /* @@ -153,8 +152,8 @@ static int acpi_dev_pm_explicit_set(struct acpi_device *adev, int state) */ int acpi_device_set_power(struct acpi_device *device, int state) { + int target_state = state; int result = 0; - bool cut_power = false; if (!device || !device->flags.power_manageable || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3_COLD)) @@ -169,11 +168,21 @@ int acpi_device_set_power(struct acpi_device *device, int state) return 0; } - if (!device->power.states[state].flags.valid) { + if (state == ACPI_STATE_D3_COLD) { + /* + * For transitions to D3cold we need to execute _PS3 and then + * possibly drop references to the power resources in use. + */ + state = ACPI_STATE_D3_HOT; + /* If _PR3 is not available, use D3hot as the target state. */ + if (!device->power.states[ACPI_STATE_D3_COLD].flags.valid) + target_state = state; + } else if (!device->power.states[state].flags.valid) { dev_warn(&device->dev, "Power state %s not supported\n", acpi_power_state_string(state)); return -ENODEV; } + if (!device->power.flags.ignore_parent && device->parent && (state < device->parent->power.state)) { dev_warn(&device->dev, @@ -183,39 +192,38 @@ int acpi_device_set_power(struct acpi_device *device, int state) return -ENODEV; } - /* For D3cold we should first transition into D3hot. */ - if (state == ACPI_STATE_D3_COLD - && device->power.states[ACPI_STATE_D3_COLD].flags.os_accessible) { - state = ACPI_STATE_D3_HOT; - cut_power = true; - } - - if (state < device->power.state && state != ACPI_STATE_D0 - && device->power.state >= ACPI_STATE_D3_HOT) { - dev_warn(&device->dev, - "Cannot transition to non-D0 state from D3\n"); - return -ENODEV; - } - /* * Transition Power * ---------------- - * In accordance with the ACPI specification first apply power (via - * power resources) and then evaluate _PSx. + * In accordance with ACPI 6, _PSx is executed before manipulating power + * resources, unless the target state is D0, in which case _PS0 is + * supposed to be executed after turning the power resources on. */ - if (device->power.flags.power_resources) { - result = acpi_power_transition(device, state); + if (state > ACPI_STATE_D0) { + /* + * According to ACPI 6, devices cannot go from lower-power + * (deeper) states to higher-power (shallower) states. + */ + if (state < device->power.state) { + dev_warn(&device->dev, "Cannot transition from %s to %s\n", + acpi_power_state_string(device->power.state), + acpi_power_state_string(state)); + return -ENODEV; + } + + result = acpi_dev_pm_explicit_set(device, state); if (result) goto end; - } - result = acpi_dev_pm_explicit_set(device, state); - if (result) - goto end; - if (cut_power) { - device->power.state = state; - state = ACPI_STATE_D3_COLD; - result = acpi_power_transition(device, state); + if (device->power.flags.power_resources) + result = acpi_power_transition(device, target_state); + } else { + if (device->power.flags.power_resources) { + result = acpi_power_transition(device, ACPI_STATE_D0); + if (result) + goto end; + } + result = acpi_dev_pm_explicit_set(device, ACPI_STATE_D0); } end: @@ -223,7 +231,7 @@ int acpi_device_set_power(struct acpi_device *device, int state) dev_warn(&device->dev, "Failed to change power state to %s\n", acpi_power_state_string(state)); } else { - device->power.state = state; + device->power.state = target_state; ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] transitioned to %s\n", device->pnp.bus_id, @@ -264,13 +272,24 @@ int acpi_bus_init_power(struct acpi_device *device) return result; if (state < ACPI_STATE_D3_COLD && device->power.flags.power_resources) { + /* Reference count the power resources. */ result = acpi_power_on_resources(device, state); if (result) return result; - result = acpi_dev_pm_explicit_set(device, state); - if (result) - return result; + if (state == ACPI_STATE_D0) { + /* + * If _PSC is not present and the state inferred from + * power resources appears to be D0, it still may be + * necessary to execute _PS0 at this point, because + * another device using the same power resources may + * have been put into D0 previously and that's why we + * see D0 here. + */ + result = acpi_dev_pm_explicit_set(device, state); + if (result) + return result; + } } else if (state == ACPI_STATE_UNKNOWN) { /* * No power resources and missing _PSC? Cross fingers and make @@ -603,12 +622,12 @@ int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p, int d_max_in) if (d_max_in < ACPI_STATE_D0 || d_max_in > ACPI_STATE_D3_COLD) return -EINVAL; - if (d_max_in > ACPI_STATE_D3_HOT) { + if (d_max_in > ACPI_STATE_D2) { 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; + d_max_in = ACPI_STATE_D2; } adev = ACPI_COMPANION(dev); |