diff options
| -rw-r--r-- | drivers/acpi/device_pm.c | 158 |
1 files changed, 92 insertions, 66 deletions
diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c index afc808e9385..fd363b57a59 100644 --- a/drivers/acpi/device_pm.c +++ b/drivers/acpi/device_pm.c @@ -403,44 +403,37 @@ EXPORT_SYMBOL(acpi_bus_can_wakeup); * @dev: Device whose preferred target power state to return. * @adev: ACPI device node corresponding to @dev. * @target_state: System state to match the resultant device state. - * @d_max_in: Deepest low-power state to take into consideration. - * @d_min_p: Location to store the upper limit of the allowed states range. - * Return value: Preferred power state of the device on success, -ENODEV - * (if there's no 'struct acpi_device' for @dev) or -EINVAL on failure + * @d_min_p: Location to store the highest power state available to the device. + * @d_max_p: Location to store the lowest power state available to the device. * - * Find the lowest power (highest number) ACPI device power state that the - * device can be in while the system is in the state represented by - * @target_state. If @d_min_p is set, the highest power (lowest number) device - * power state that @dev can be in for the given system sleep state is stored - * at the location pointed to by it. + * Find the lowest power (highest number) and highest power (lowest number) ACPI + * device power states that the device can be in while the system is in the + * state represented by @target_state. Store the integer numbers representing + * those stats in the memory locations pointed to by @d_max_p and @d_min_p, + * respectively. * * Callers must ensure that @dev and @adev are valid pointers and that @adev * actually corresponds to @dev before using this function. + * + * Returns 0 on success or -ENODATA when one of the ACPI methods fails or + * returns a value that doesn't make sense. The memory locations pointed to by + * @d_max_p and @d_min_p are only modified on success. */ static int acpi_dev_pm_get_state(struct device *dev, struct acpi_device *adev, - u32 target_state, int d_max_in, int *d_min_p) + u32 target_state, int *d_min_p, int *d_max_p) { - char acpi_method[] = "_SxD"; - unsigned long long d_min, d_max; + char method[] = { '_', 'S', '0' + target_state, 'D', '\0' }; + acpi_handle handle = adev->handle; + unsigned long long ret; + int d_min, d_max; bool wakeup = false; + acpi_status status; - if (d_max_in < ACPI_STATE_D0 || d_max_in > ACPI_STATE_D3_COLD) - return -EINVAL; - - 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' + target_state; /* - * If the sleep state is S0, the lowest limit from ACPI is D3, - * 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. + * If the system state is S0, the lowest power state the device can be + * in is D3cold, unless the device has _S0W and is supposed to signal + * wakeup, in which case the return value of _S0W has to be used as the + * lowest power state available to the device. */ d_min = ACPI_STATE_D0; d_max = ACPI_STATE_D3_COLD; @@ -449,12 +442,30 @@ static int acpi_dev_pm_get_state(struct device *dev, struct acpi_device *adev, * If present, _SxD methods return the minimum D-state (highest power * state) we can use for the corresponding S-states. Otherwise, the * minimum D-state is D0 (ACPI 3.x). - * - * NOTE: We rely on acpi_evaluate_integer() not clobbering the integer - * provided -- that's our fault recovery, we ignore retval. */ if (target_state > ACPI_STATE_S0) { - acpi_evaluate_integer(adev->handle, acpi_method, NULL, &d_min); + /* + * We rely on acpi_evaluate_integer() not clobbering the integer + * provided if AE_NOT_FOUND is returned. + */ + ret = d_min; + status = acpi_evaluate_integer(handle, method, NULL, &ret); + if ((ACPI_FAILURE(status) && status != AE_NOT_FOUND) + || ret > ACPI_STATE_D3_COLD) + return -ENODATA; + + /* + * We need to handle legacy systems where D3hot and D3cold are + * the same and 3 is returned in both cases, so fall back to + * D3cold if D3hot is not a valid state. + */ + if (!adev->power.states[ret].flags.valid) { + if (ret == ACPI_STATE_D3_HOT) + ret = ACPI_STATE_D3_COLD; + else + return -ENODATA; + } + d_min = ret; wakeup = device_may_wakeup(dev) && adev->wakeup.flags.valid && adev->wakeup.sleep_state >= target_state; } else if (dev_pm_qos_flags(dev, PM_QOS_FLAG_REMOTE_WAKEUP) != @@ -470,36 +481,29 @@ static int acpi_dev_pm_get_state(struct device *dev, struct acpi_device *adev, * can wake the system. _S0W may be valid, too. */ if (wakeup) { - acpi_status status; - - acpi_method[3] = 'W'; - status = acpi_evaluate_integer(adev->handle, acpi_method, NULL, - &d_max); - if (ACPI_FAILURE(status)) { - if (target_state != ACPI_STATE_S0 || - status != AE_NOT_FOUND) + method[3] = 'W'; + status = acpi_evaluate_integer(handle, method, NULL, &ret); + if (status == AE_NOT_FOUND) { + if (target_state > ACPI_STATE_S0) d_max = d_min; - } else if (d_max < d_min) { - /* Warn the user of the broken DSDT */ - printk(KERN_WARNING "ACPI: Wrong value from %s\n", - acpi_method); - /* Sanitize it */ - d_min = d_max; + } else if (ACPI_SUCCESS(status) && ret <= ACPI_STATE_D3_COLD) { + /* Fall back to D3cold if ret is not a valid state. */ + if (!adev->power.states[ret].flags.valid) + ret = ACPI_STATE_D3_COLD; + + d_max = ret > d_min ? ret : d_min; + } else { + return -ENODATA; } } - if (d_max_in < d_min) - return -EINVAL; if (d_min_p) *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; + + if (d_max_p) + *d_max_p = d_max; + + return 0; } /** @@ -508,7 +512,8 @@ static int acpi_dev_pm_get_state(struct device *dev, struct acpi_device *adev, * @d_min_p: Location to store the upper limit of the allowed states range. * @d_max_in: Deepest low-power state to take into consideration. * Return value: Preferred power state of the device on success, -ENODEV - * (if there's no 'struct acpi_device' for @dev) or -EINVAL on failure + * if there's no 'struct acpi_device' for @dev, -EINVAL if @d_max_in is + * incorrect, or -ENODATA on ACPI method failure. * * The caller must ensure that @dev is valid before using this function. */ @@ -516,14 +521,39 @@ int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p, int d_max_in) { acpi_handle handle = DEVICE_ACPI_HANDLE(dev); struct acpi_device *adev; + int ret, d_max; + + if (d_max_in < ACPI_STATE_D0 || d_max_in > ACPI_STATE_D3_COLD) + return -EINVAL; + + 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; + } if (!handle || acpi_bus_get_device(handle, &adev)) { dev_dbg(dev, "ACPI handle without context in %s!\n", __func__); return -ENODEV; } - return acpi_dev_pm_get_state(dev, adev, acpi_target_system_state(), - d_max_in, d_min_p); + ret = acpi_dev_pm_get_state(dev, adev, acpi_target_system_state(), + d_min_p, &d_max); + if (ret) + return ret; + + if (d_max_in < *d_min_p) + return -EINVAL; + + if (d_max > d_max_in) { + for (d_max = d_max_in; d_max > *d_min_p; d_max--) { + if (adev->power.states[d_max].flags.valid) + break; + } + } + return d_max; } EXPORT_SYMBOL(acpi_pm_device_sleep_state); @@ -674,17 +704,13 @@ struct acpi_device *acpi_dev_pm_get_node(struct device *dev) static int acpi_dev_pm_low_power(struct device *dev, struct acpi_device *adev, u32 system_state) { - int power_state; + int ret, state; if (!acpi_device_power_manageable(adev)) return 0; - power_state = acpi_dev_pm_get_state(dev, adev, system_state, - ACPI_STATE_D3_COLD, NULL); - if (power_state < ACPI_STATE_D0 || power_state > ACPI_STATE_D3_COLD) - return -EIO; - - return acpi_device_set_power(adev, power_state); + ret = acpi_dev_pm_get_state(dev, adev, system_state, NULL, &state); + return ret ? ret : acpi_device_set_power(adev, state); } /** |