ACPI / scan: Define non-empty device removal handler
If an ACPI namespace node is removed (usually, as a result of a table unload), and there is a data object attached to that node, acpi_ns_delete_node() executes the removal handler submitted to acpi_attach_data() for that object. That handler is currently empty for struct acpi_device objects, so it is necessary to detach those objects from the corresponding ACPI namespace nodes in advance every time a table unload may happen. That is cumbersome and inefficient and leads to some design constraints that turn out to be quite inconvenient (in particular, struct acpi_device objects cannot be registered for namespace nodes representing devices that are not reported as present or functional by _STA). For this reason, introduce a non-empty removal handler for ACPI device objects that will unregister them when their ACPI namespace nodes go away. This code modification alone should not change functionality except for the ordering of the ACPI hotplug workqueue which should not matter (without subsequent code changes). Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Showing
想要评论请 注册 或 登录