diff options
| author | Bjorn Helgaas <bjorn.helgaas@hp.com> | 2009-09-21 19:30:11 +0000 |
|---|---|---|
| committer | Len Brown <len.brown@intel.com> | 2009-09-25 14:24:32 -0400 |
| commit | e3b87f8a9d5a61f6367c66d1bb0a4e19d251194d (patch) | |
| tree | 9054b93f90f9de3b536f656727c947c1d34b4519 | |
| parent | 778cbc1d3abd434b6d882714630235e3711bb15b (diff) | |
ACPI: handle re-enumeration, when acpi_devices might already exist
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>
| -rw-r--r-- | drivers/acpi/scan.c | 19 |
1 files changed, 11 insertions, 8 deletions
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 954bd01f295..2c4cac576a7 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -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)) { |