From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Date: Sun, 16 Apr 2017 23:20:48 +0000 (+0200)
Subject: ACPI / scan: Avoid enumerating devices more than once
X-Git-Tag: v4.12-rc1~163^2~2^2
X-Git-Url: http://git.samba.org/samba.git/?p=sfrench%2Fcifs-2.6.git;a=commitdiff_plain;h=c381fc3a1bbfc9d780048a0b94afd162e4c3815b

ACPI / scan: Avoid enumerating devices more than once

acpi_bus_attach() does not check the visited flag for devices that
have been enumerated already and some of them may be enumerated
for multiple times as a result, because some callers of
acpi_bus_scan() don't check the visited flag either.

For this reason, modify acpi_bus_attach() to check the visited flag
and avoid enumerating devices that have already been enumerated.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Joey Lee <jlee@suse.com>
---

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index f74bc0d28692..c26931067415 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1840,6 +1840,8 @@ static void acpi_bus_attach(struct acpi_device *device)
 			device->flags.power_manageable = 0;
 
 		device->flags.initialized = true;
+	} else if (device->flags.visited) {
+		goto ok;
 	}
 
 	ret = acpi_scan_attach_handler(device);