From 19cd847ab24fefe9e50101ec94479e0400a08650 Mon Sep 17 00:00:00 2001 From: Zhang Rui Date: Thu, 28 Aug 2008 10:05:06 +0800 Subject: ACPI: fix hotplug race The hotplug notification handler and drivers' notification handler all run in one workqueue. Before hotplug removes an acpi device, the device driver's notification handler is already be recorded to run just after global notification handler. After hotplug notification handler runs, acpica will notice a NULL notification handler and crash. So now we run run hotplug in another workqueue and wait for all acpi notication handlers finish. This was found in battery hotplug, but actually all hotplug can be affected. Signed-off-by: Zhang Rui Signed-off-by: Shaohua Li Signed-off-by: Len Brown --- drivers/acpi/osl.c | 46 +++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 41 insertions(+), 5 deletions(-) (limited to 'drivers/acpi/osl.c') diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c index 235a1386888..750e0df1560 100644 --- a/drivers/acpi/osl.c +++ b/drivers/acpi/osl.c @@ -682,6 +682,22 @@ static void acpi_os_execute_deferred(struct work_struct *work) return; } +static void acpi_os_execute_hp_deferred(struct work_struct *work) +{ + struct acpi_os_dpc *dpc = container_of(work, struct acpi_os_dpc, work); + if (!dpc) { + printk(KERN_ERR PREFIX "Invalid (NULL) context\n"); + return; + } + + acpi_os_wait_events_complete(NULL); + + dpc->function(dpc->context); + kfree(dpc); + + return; +} + /******************************************************************************* * * FUNCTION: acpi_os_execute @@ -697,12 +713,13 @@ static void acpi_os_execute_deferred(struct work_struct *work) * ******************************************************************************/ -acpi_status acpi_os_execute(acpi_execute_type type, - acpi_osd_exec_callback function, void *context) +static acpi_status __acpi_os_execute(acpi_execute_type type, + acpi_osd_exec_callback function, void *context, int hp) { acpi_status status = AE_OK; struct acpi_os_dpc *dpc; struct workqueue_struct *queue; + int ret; ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Scheduling function [%p(%p)] for deferred execution.\n", function, context)); @@ -726,9 +743,17 @@ acpi_status acpi_os_execute(acpi_execute_type type, dpc->function = function; dpc->context = context; - INIT_WORK(&dpc->work, acpi_os_execute_deferred); - queue = (type == OSL_NOTIFY_HANDLER) ? kacpi_notify_wq : kacpid_wq; - if (!queue_work(queue, &dpc->work)) { + if (!hp) { + INIT_WORK(&dpc->work, acpi_os_execute_deferred); + queue = (type == OSL_NOTIFY_HANDLER) ? + kacpi_notify_wq : kacpid_wq; + ret = queue_work(queue, &dpc->work); + } else { + INIT_WORK(&dpc->work, acpi_os_execute_hp_deferred); + ret = schedule_work(&dpc->work); + } + + if (!ret) { ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Call to queue_work() failed.\n")); status = AE_ERROR; @@ -737,8 +762,19 @@ acpi_status acpi_os_execute(acpi_execute_type type, return_ACPI_STATUS(status); } +acpi_status acpi_os_execute(acpi_execute_type type, + acpi_osd_exec_callback function, void *context) +{ + return __acpi_os_execute(type, function, context, 0); +} EXPORT_SYMBOL(acpi_os_execute); +acpi_status acpi_os_hotplug_execute(acpi_osd_exec_callback function, + void *context) +{ + return __acpi_os_execute(0, function, context, 1); +} + void acpi_os_wait_events_complete(void *context) { flush_workqueue(kacpid_wq); -- cgit v1.2.3-70-g09d2