diff options
| -rw-r--r-- | drivers/acpi/device_pm.c | 8 | ||||
| -rw-r--r-- | drivers/acpi/internal.h | 2 | ||||
| -rw-r--r-- | drivers/acpi/scan.c | 46 |
3 files changed, 40 insertions, 16 deletions
diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c index 717afcdb5f4a..08dc3ec7e892 100644 --- a/drivers/acpi/device_pm.c +++ b/drivers/acpi/device_pm.c @@ -1123,6 +1123,14 @@ int acpi_dev_pm_attach(struct device *dev, bool power_on) if (dev->pm_domain) return -EEXIST; + /* + * Only attach the power domain to the first device if the + * companion is shared by multiple. This is to prevent doing power + * management twice. + */ + if (!acpi_device_is_first_physical_node(adev, dev)) + return -EBUSY; + acpi_add_pm_notifier(adev, dev, acpi_pm_notify_work_func); dev->pm_domain = &acpi_general_pm_domain; if (power_on) { diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h index 4683a96932b9..f6aefe984941 100644 --- a/drivers/acpi/internal.h +++ b/drivers/acpi/internal.h @@ -97,6 +97,8 @@ void acpi_device_add_finalize(struct acpi_device *device); void acpi_free_pnp_ids(struct acpi_device_pnp *pnp); bool acpi_device_is_present(struct acpi_device *adev); bool acpi_device_is_battery(struct acpi_device *adev); +bool acpi_device_is_first_physical_node(struct acpi_device *adev, + const struct device *dev); /* -------------------------------------------------------------------------- Power Resource diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index ec256352f423..89ff6d2eef8a 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -226,6 +226,35 @@ static int create_of_modalias(struct acpi_device *acpi_dev, char *modalias, return len; } +/** + * acpi_device_is_first_physical_node - Is given dev first physical node + * @adev: ACPI companion device + * @dev: Physical device to check + * + * Function checks if given @dev is the first physical devices attached to + * the ACPI companion device. This distinction is needed in some cases + * where the same companion device is shared between many physical devices. + * + * Note that the caller have to provide valid @adev pointer. + */ +bool acpi_device_is_first_physical_node(struct acpi_device *adev, + const struct device *dev) +{ + bool ret = false; + + mutex_lock(&adev->physical_node_lock); + if (!list_empty(&adev->physical_node_list)) { + const struct acpi_device_physical_node *node; + + node = list_first_entry(&adev->physical_node_list, + struct acpi_device_physical_node, node); + ret = node->dev == dev; + } + mutex_unlock(&adev->physical_node_lock); + + return ret; +} + /* * acpi_companion_match() - Can we match via ACPI companion device * @dev: Device in question @@ -250,7 +279,6 @@ static int create_of_modalias(struct acpi_device *acpi_dev, char *modalias, static struct acpi_device *acpi_companion_match(const struct device *dev) { struct acpi_device *adev; - struct mutex *physical_node_lock; adev = ACPI_COMPANION(dev); if (!adev) @@ -259,21 +287,7 @@ static struct acpi_device *acpi_companion_match(const struct device *dev) if (list_empty(&adev->pnp.ids)) return NULL; - physical_node_lock = &adev->physical_node_lock; - mutex_lock(physical_node_lock); - if (list_empty(&adev->physical_node_list)) { - adev = NULL; - } else { - const struct acpi_device_physical_node *node; - - node = list_first_entry(&adev->physical_node_list, - struct acpi_device_physical_node, node); - if (node->dev != dev) - adev = NULL; - } - mutex_unlock(physical_node_lock); - - return adev; + return acpi_device_is_first_physical_node(adev, dev) ? adev : NULL; } static int __acpi_device_uevent_modalias(struct acpi_device *adev, |