• Rafael J. Wysocki's avatar
    ACPI / ACPICA: Fix reference counting problems with GPE handlers · 28f4f8a9
    Rafael J. Wysocki authored
    If a handler is installed for a GPE associated with an AML method and
    such that it cannot wake up the system from sleep states, the GPE
    remains enabled after the handler has been installed, although it
    should be disabled in that case to avoid spurious execution of the
    handler.
    
    Fix this issue by making acpi_install_gpe_handler() disable GPEs
    that were previously associated with AML methods and cannot wake up
    the system from sleep states.
    
    Analogously, make acpi_remove_gpe_handler() enable the GPEs that
    are associated with AML methods after their handlers have been
    removed and cannot wake up the system from sleep states.  In addition
    to that, fix a code ordering issue in acpi_remove_gpe_handler() that
    renders the locking ineffective (ACPI_MTX_EVENTS is released
    temporarily in the middle of the routine to wait for the completion
    of events already in progress).
    
    For this purpose introduce acpi_raw_disable_gpe() and
    acpi_raw_enable_gpe() to be called with acpi_gbl_gpe_lock held
    and rework acpi_disable_gpe() and acpi_enable_gpe(), respectively, to
    use them.  Also rework acpi_gpe_can_wake() to use
    acpi_raw_disable_gpe() instead of calling acpi_disable_gpe() after
    releasing the lock to avoid the possible theoretical race with
    acpi_install_gpe_handler().
    Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
    Cc: "Moore, Robert" <robert.moore@intel.com>
    Cc: Lin Ming <ming.m.lin@intel.com>
    Signed-off-by: default avatarLen Brown <len.brown@intel.com>
    28f4f8a9
aclocal.h 34.5 KB