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由 Rafael J. Wysocki 提交于
The ACPI device enumeration code in Linux assumes that buttons always are wakeup devices, so it calls acpi_setup_gpe_for_wake() for them which leads to undesirable side effects. Namely, that function sets up implicit device wake notification mechanism for a given GPE if there is no handler method in the ACPI namespace, which from the ACPICA's perspective means that there always is a way to handle that GPE if enabled. However, we don't handle wake notify events for buttons, so if there are no handler methods for their GPEs in the namespace, enabling a button GPE at run time leads to a GPE storm in some cases (the GPE triggers, ACPICA carries out the implicit wake notification for it which isn't handled, so the GPE triggers again and so on). To prevent that from happening use acpi_mark_gpe_for_wake() instead of acpi_setup_gpe_for_wake() for buttons which will cause ACPICA to only enable button GPEs if there are handler methods for the in the namespace. Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
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