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authorThomas Renninger <trenn@suse.de>2010-01-29 17:48:52 +0100
committerLen Brown <len.brown@intel.com>2010-01-31 21:43:32 -0500
commit7779688fc3d1ceddad84846a7b0affbe8e78ec6e (patch)
treefff56e1fea8656749666280b857ecac04560e70a /drivers/acpi/scan.c
parentd2f6650a950dadd20667a04a9dc785f240d43695 (diff)
downloadlinux-linaro-android-7779688fc3d1ceddad84846a7b0affbe8e78ec6e.tar.gz
ACPI: acpi_bus_{scan,bus,add}: return -ENODEV if no device was found
Callers (acpi_memhotplug.c, dock.c and others) check for the return value of acpi_bus_add() and assume a valid device was returned in case zero was returned. Thus return -ENODEV if no device was found in acpi_bus_scan and propagate this through acpi_bus_add and acpi_bus_start. Also remove a confusing comment in acpiphp_glue.c, acpi_bus_scan will and cannot invoke if acpi_bus_add returns no valid device. Signed-off-by: Thomas Renninger <trenn@suse.de> Acked-by: Bjorn Helgaas <bjorn.helgaas@hp.com> Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'drivers/acpi/scan.c')
-rw-r--r--drivers/acpi/scan.c24
1 files changed, 19 insertions, 5 deletions
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 8044583f303..3e009674f33 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1336,9 +1336,25 @@ static int acpi_bus_scan(acpi_handle handle, struct acpi_bus_ops *ops,
if (child)
*child = device;
- return 0;
+
+ if (device)
+ return 0;
+ else
+ return -ENODEV;
}
+/*
+ * acpi_bus_add and acpi_bus_start
+ *
+ * scan a given ACPI tree and (probably recently hot-plugged)
+ * create and add or starts found devices.
+ *
+ * If no devices were found -ENODEV is returned which does not
+ * mean that this is a real error, there just have been no suitable
+ * ACPI objects in the table trunk from which the kernel could create
+ * a device and add/start an appropriate driver.
+ */
+
int
acpi_bus_add(struct acpi_device **child,
struct acpi_device *parent, acpi_handle handle, int type)
@@ -1348,8 +1364,7 @@ acpi_bus_add(struct acpi_device **child,
memset(&ops, 0, sizeof(ops));
ops.acpi_op_add = 1;
- acpi_bus_scan(handle, &ops, child);
- return 0;
+ return acpi_bus_scan(handle, &ops, child);
}
EXPORT_SYMBOL(acpi_bus_add);
@@ -1363,8 +1378,7 @@ int acpi_bus_start(struct acpi_device *device)
memset(&ops, 0, sizeof(ops));
ops.acpi_op_start = 1;
- acpi_bus_scan(device->handle, &ops, NULL);
- return 0;
+ return acpi_bus_scan(device->handle, &ops, NULL);
}
EXPORT_SYMBOL(acpi_bus_start);