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ACPI: handle re-enumeration, when acpi_devices might already exist

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acpi_bus_scan() traverses the namespace to enumerate devices and uses
acpi_add_single_object() to create acpi_devices.  When the platform
notifies us of a hot-plug event, we need to traverse part of the namespace
again to figure out what appeared or disappeared.  (We don't yet call
acpi_bus_scan() during hot-plug, but I plan to do that in the future.)

This patch makes acpi_add_single_object() notice when we already have
an acpi_device, so we don't need to make a new one.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>
This commit is contained in:
Bjorn Helgaas 2009-09-21 19:30:11 +00:00 committed by Len Brown
parent 778cbc1d3a
commit e3b87f8a9d
1 changed files with 11 additions and 8 deletions
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19
drivers/acpi/scan.c
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@ -1400,10 +1400,10 @@ static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl,
void *context, void **return_value)
{
struct acpi_bus_ops *ops = context;
struct acpi_device *device = NULL;
acpi_status status;
int type;
unsigned long long sta;
struct acpi_device *device;
acpi_status status;
int result;
result = acpi_bus_type_and_status(handle, &type, &sta);
@ -1414,13 +1414,16 @@ static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl,
!(sta & ACPI_STA_DEVICE_FUNCTIONING))
return AE_CTRL_DEPTH;
if (ops->acpi_op_add)
status = acpi_add_single_object(&device, handle, type, sta,
ops);
else
status = acpi_bus_get_device(handle, &device);
/*
* We may already have an acpi_device from a previous enumeration. If
* so, we needn't add it again, but we may still have to start it.
*/
device = NULL;
acpi_bus_get_device(handle, &device);
if (ops->acpi_op_add && !device)
acpi_add_single_object(&device, handle, type, sta, ops);
if (ACPI_FAILURE(status))
if (!device)
return AE_CTRL_DEPTH;
if (ops->acpi_op_start && !(ops->acpi_op_add)) {