From: Rafael J. Wysocki <[email protected]> If there are no devices whose enumeration has been deferred after the first pass in acpi_bus_scan(), the second pass is not necssary, so avoid it with the help of a new static variable.
Signed-off-by: Rafael J. Wysocki <[email protected]> --- drivers/acpi/scan.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) Index: linux-pm/drivers/acpi/scan.c =================================================================== --- linux-pm.orig/drivers/acpi/scan.c +++ linux-pm/drivers/acpi/scan.c @@ -1910,6 +1910,8 @@ static void acpi_scan_dep_init(struct ac mutex_unlock(&acpi_dep_list_lock); } +static bool acpi_bus_scan_second_pass; + static acpi_status acpi_bus_check_add(acpi_handle handle, bool check_dep, struct acpi_device **adev_p) { @@ -1934,8 +1936,10 @@ static acpi_status acpi_bus_check_add(ac if (type == ACPI_BUS_TYPE_DEVICE && check_dep) { u32 count = acpi_scan_check_dep(handle); /* Bail out if the number of recorded dependencies is not 0. */ - if (count > 0) + if (count > 0) { + acpi_bus_scan_second_pass = true; return AE_CTRL_DEPTH; + } } acpi_add_single_object(&device, handle, type, sta); @@ -2136,6 +2140,8 @@ int acpi_bus_scan(acpi_handle handle) { struct acpi_device *device = NULL; + acpi_bus_scan_second_pass = false; + /* Pass 1: Avoid enumerating devices with missing dependencies. */ if (ACPI_SUCCESS(acpi_bus_check_add(handle, true, &device))) @@ -2148,6 +2154,9 @@ int acpi_bus_scan(acpi_handle handle) acpi_bus_attach(device, true); + if (!acpi_bus_scan_second_pass) + return 0; + /* Pass 2: Enumerate all of the remaining devices. */ device = NULL;
