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author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2013-01-27 20:17:29 (GMT) |
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committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2013-01-27 20:17:29 (GMT) |
commit | c511cc1990bbc263c3f8a2ef4d7d613a3b40ffe2 (patch) | |
tree | 4919ff638fa0606267deec1d225fed199afb11e5 /drivers | |
parent | bfee26dba0f373ebe4e6f0b293d078b02f9f7f69 (diff) | |
download | linux-fsl-qoriq-c511cc1990bbc263c3f8a2ef4d7d613a3b40ffe2.tar.xz |
ACPI / scan: Make namespace scanning and trimming mutually exclusive
There is no guarantee that acpi_bus_scan() and acpi_bus_trim() will
not be run in parallel for the same scope of the ACPI namespace,
which may lead to a great deal of confusion, so introduce a new mutex
to prevent that from happening.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/acpi/scan.c | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index d37f290..4375465 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -52,6 +52,7 @@ static const struct acpi_device_id acpi_platform_device_ids[] = { static LIST_HEAD(acpi_device_list); static LIST_HEAD(acpi_bus_id_list); +static DEFINE_MUTEX(acpi_scan_lock); DEFINE_MUTEX(acpi_device_lock); LIST_HEAD(acpi_wakeup_device_list); @@ -1587,19 +1588,22 @@ static acpi_status acpi_bus_device_attach(acpi_handle handle, u32 lvl_not_used, int acpi_bus_scan(acpi_handle handle) { void *device = NULL; + int error = 0; + + mutex_lock(&acpi_scan_lock); if (ACPI_SUCCESS(acpi_bus_check_add(handle, 0, NULL, &device))) acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX, acpi_bus_check_add, NULL, NULL, &device); if (!device) - return -ENODEV; - - if (ACPI_SUCCESS(acpi_bus_device_attach(handle, 0, NULL, NULL))) + error = -ENODEV; + else if (ACPI_SUCCESS(acpi_bus_device_attach(handle, 0, NULL, NULL))) acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX, acpi_bus_device_attach, NULL, NULL, NULL); - return 0; + mutex_unlock(&acpi_scan_lock); + return error; } EXPORT_SYMBOL(acpi_bus_scan); @@ -1628,6 +1632,8 @@ static acpi_status acpi_bus_remove(acpi_handle handle, u32 lvl_not_used, void acpi_bus_trim(struct acpi_device *start) { + mutex_lock(&acpi_scan_lock); + /* * Execute acpi_bus_device_detach() as a post-order callback to detach * all ACPI drivers from the device nodes being removed. @@ -1642,6 +1648,8 @@ void acpi_bus_trim(struct acpi_device *start) acpi_walk_namespace(ACPI_TYPE_ANY, start->handle, ACPI_UINT32_MAX, NULL, acpi_bus_remove, NULL, NULL); acpi_bus_remove(start->handle, 0, NULL, NULL); + + mutex_unlock(&acpi_scan_lock); } EXPORT_SYMBOL_GPL(acpi_bus_trim); |