From 72945b2b90a5554975b8f72673ab7139d232a121 Mon Sep 17 00:00:00 2001
From: Len Brown
Date: Wed, 12 Jul 2006 22:46:42 -0400
Subject: [PATCH] Revert "ACPI: execute Notify() handlers on new thread"

This effectively reverts commit b8d35192c55fb055792ff0641408eaaec7c88988
by reverts acpi_os_queue_for_execution() to what it was before that,
except it changes the name to acpi_os_execute() to match ACPICA
20060512.

Signed-off-by: Len Brown <len.brown@intel.com>

[ The thread execution doesn't actually solve the bug it set out to
  solve (see

	http://bugzilla.kernel.org/show_bug.cgi?id=5534

  for more details) because the new events can get caught behind the AML
  semaphore or other serialization.  And when that happens, the notify
  threads keep on piling up until the system dies. ]

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---
 drivers/acpi/osl.c | 60 ++++++++++++++++++++++--------------------------------
 1 file changed, 24 insertions(+), 36 deletions(-)

(limited to 'drivers/acpi')

diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
index 47dfde95b8f8..b7d1514cd199 100644
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -36,7 +36,6 @@
 #include <linux/delay.h>
 #include <linux/workqueue.h>
 #include <linux/nmi.h>
-#include <linux/kthread.h>
 #include <acpi/acpi.h>
 #include <asm/io.h>
 #include <acpi/acpi_bus.h>
@@ -583,16 +582,6 @@ static void acpi_os_execute_deferred(void *context)
 	return;
 }
 
-static int acpi_os_execute_thread(void *context)
-{
-	struct acpi_os_dpc *dpc = (struct acpi_os_dpc *)context;
-	if (dpc) {
-		dpc->function(dpc->context);
-		kfree(dpc);
-	}
-	do_exit(0);
-}
-
 /*******************************************************************************
  *
  * FUNCTION:    acpi_os_execute
@@ -614,10 +603,16 @@ acpi_status acpi_os_execute(acpi_execute_type type,
 	acpi_status status = AE_OK;
 	struct acpi_os_dpc *dpc;
 	struct work_struct *task;
-	struct task_struct *p;
+
+	ACPI_FUNCTION_TRACE("os_queue_for_execution");
+
+	ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
+			  "Scheduling function [%p(%p)] for deferred execution.\n",
+			  function, context));
 
 	if (!function)
-		return AE_BAD_PARAMETER;
+		return_ACPI_STATUS(AE_BAD_PARAMETER);
+
 	/*
 	 * Allocate/initialize DPC structure.  Note that this memory will be
 	 * freed by the callee.  The kernel handles the tq_struct list  in a
@@ -628,34 +623,27 @@ acpi_status acpi_os_execute(acpi_execute_type type,
 	 * We can save time and code by allocating the DPC and tq_structs
 	 * from the same memory.
 	 */
-	if (type == OSL_NOTIFY_HANDLER) {
-		dpc = kmalloc(sizeof(struct acpi_os_dpc), GFP_KERNEL);
-	} else {
-		dpc = kmalloc(sizeof(struct acpi_os_dpc) +
-				sizeof(struct work_struct), GFP_ATOMIC);
-	}
+
+	dpc =
+	    kmalloc(sizeof(struct acpi_os_dpc) + sizeof(struct work_struct),
+		    GFP_ATOMIC);
 	if (!dpc)
-		return AE_NO_MEMORY;
+		return_ACPI_STATUS(AE_NO_MEMORY);
+
 	dpc->function = function;
 	dpc->context = context;
 
-	if (type == OSL_NOTIFY_HANDLER) {
-		p = kthread_create(acpi_os_execute_thread, dpc, "kacpid_notify");
-		if (!IS_ERR(p)) {
-			wake_up_process(p);
-		} else {
-			status = AE_NO_MEMORY;
-			kfree(dpc);
-		}
-	} else {
-		task = (void *)(dpc + 1);
-		INIT_WORK(task, acpi_os_execute_deferred, (void *)dpc);
-		if (!queue_work(kacpid_wq, task)) {
-			status = AE_ERROR;
-			kfree(dpc);
-		}
+	task = (void *)(dpc + 1);
+	INIT_WORK(task, acpi_os_execute_deferred, (void *)dpc);
+
+	if (!queue_work(kacpid_wq, task)) {
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+				  "Call to queue_work() failed.\n"));
+		kfree(dpc);
+		status = AE_ERROR;
 	}
-	return status;
+
+	return_ACPI_STATUS(status);
 }
 
 EXPORT_SYMBOL(acpi_os_execute);
-- 
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