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author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2012-11-02 13:09:08 +0100 |
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committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2012-11-15 00:18:20 +0100 |
commit | 3ae45a27df74358b4bcd3d5a67e47ad734a48945 (patch) | |
tree | 17ffd507fd96a4567fa2d6076b497298384d0945 /drivers/acpi | |
parent | c5b18e22e74dc7dbd3f7729997a3a553ce761d2b (diff) | |
download | op-kernel-dev-3ae45a27df74358b4bcd3d5a67e47ad734a48945.zip op-kernel-dev-3ae45a27df74358b4bcd3d5a67e47ad734a48945.tar.gz |
ACPI: Make seemingly useless check in osl.c more understandable
There is a seemingly useless check in drivers/acpi/osl.c added by
commit bc73675 (ACPI: fixes a false alarm from lockdep), which really
is necessary to avoid false positive lockdep complaints. Document
this and rearrange the code related to it so that it makes fewer
checks.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
Diffstat (limited to 'drivers/acpi')
-rw-r--r-- | drivers/acpi/osl.c | 21 |
1 files changed, 13 insertions, 8 deletions
diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c index 7dfe91d..6dc4a2b 100644 --- a/drivers/acpi/osl.c +++ b/drivers/acpi/osl.c @@ -932,7 +932,7 @@ static acpi_status __acpi_os_execute(acpi_execute_type type, * having a static work_struct. */ - dpc = kmalloc(sizeof(struct acpi_os_dpc), GFP_ATOMIC); + dpc = kzalloc(sizeof(struct acpi_os_dpc), GFP_ATOMIC); if (!dpc) return AE_NO_MEMORY; @@ -944,17 +944,22 @@ static acpi_status __acpi_os_execute(acpi_execute_type type, * because the hotplug code may call driver .remove() functions, * which invoke flush_scheduled_work/acpi_os_wait_events_complete * to flush these workqueues. + * + * To prevent lockdep from complaining unnecessarily, make sure that + * there is a different static lockdep key for each workqueue by using + * INIT_WORK() for each of them separately. */ - queue = hp ? kacpi_hotplug_wq : - (type == OSL_NOTIFY_HANDLER ? kacpi_notify_wq : kacpid_wq); - dpc->wait = hp ? 1 : 0; - - if (queue == kacpi_hotplug_wq) + if (hp) { + queue = kacpi_hotplug_wq; + dpc->wait = 1; INIT_WORK(&dpc->work, acpi_os_execute_deferred); - else if (queue == kacpi_notify_wq) + } else if (type == OSL_NOTIFY_HANDLER) { + queue = kacpi_notify_wq; INIT_WORK(&dpc->work, acpi_os_execute_deferred); - else + } else { + queue = kacpid_wq; INIT_WORK(&dpc->work, acpi_os_execute_deferred); + } /* * On some machines, a software-initiated SMI causes corruption unless |