1 files changed, 109 insertions, 44 deletions

diff --git a/drivers/acpi/acpica/evgpe.c b/drivers/acpi/acpica/evgpe.c
index b9d50ef9f3e..deb26f4c662 100644
--- a/drivers/acpi/acpica/evgpe.c
+++ b/drivers/acpi/acpica/evgpe.c
@@ -60,7 +60,8 @@ static void ACPI_SYSTEM_XFACE acpi_ev_asynch_execute_gpe_method(void *context);
  *
  * RETURN:      Status
  *
- * DESCRIPTION: Updates GPE register enable masks based on the GPE type
+ * DESCRIPTION: Updates GPE register enable masks based upon whether there are
+ *              references (either wake or run) to this GPE
  *
  ******************************************************************************/
 
@@ -81,14 +82,20 @@ acpi_ev_update_gpe_enable_masks(struct acpi_gpe_event_info *gpe_event_info)
 	    (1 <<
 	     (gpe_event_info->gpe_number - gpe_register_info->base_gpe_number));
 
+	/* Clear the wake/run bits up front */
+
 	ACPI_CLEAR_BIT(gpe_register_info->enable_for_wake, register_bit);
 	ACPI_CLEAR_BIT(gpe_register_info->enable_for_run, register_bit);
 
-	if (gpe_event_info->runtime_count)
+	/* Set the mask bits only if there are references to this GPE */
+
+	if (gpe_event_info->runtime_count) {
 		ACPI_SET_BIT(gpe_register_info->enable_for_run, register_bit);
+	}
 
-	if (gpe_event_info->wakeup_count)
+	if (gpe_event_info->wakeup_count) {
 		ACPI_SET_BIT(gpe_register_info->enable_for_wake, register_bit);
+	}
 
 	return_ACPI_STATUS(AE_OK);
 }
@@ -101,7 +108,10 @@ acpi_ev_update_gpe_enable_masks(struct acpi_gpe_event_info *gpe_event_info)
  *
  * RETURN:      Status
  *
- * DESCRIPTION: Enable a GPE based on the GPE type
+ * DESCRIPTION: Hardware-enable a GPE. Always enables the GPE, regardless
+ *              of type or number of references.
+ *
+ * Note: The GPE lock should be already acquired when this function is called.
  *
  ******************************************************************************/
 
@@ -109,20 +119,36 @@ acpi_status acpi_ev_enable_gpe(struct acpi_gpe_event_info *gpe_event_info)
 {
 	acpi_status status;
 
+
 	ACPI_FUNCTION_TRACE(ev_enable_gpe);
 
-	/* Make sure HW enable masks are updated */
+
+	/*
+	 * We will only allow a GPE to be enabled if it has either an
+	 * associated method (_Lxx/_Exx) or a handler. Otherwise, the
+	 * GPE will be immediately disabled by acpi_ev_gpe_dispatch the
+	 * first time it fires.
+	 */
+	if (!(gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK)) {
+		return_ACPI_STATUS(AE_NO_HANDLER);
+	}
+
+	/* Ensure the HW enable masks are current */
 
 	status = acpi_ev_update_gpe_enable_masks(gpe_event_info);
-	if (ACPI_FAILURE(status))
+	if (ACPI_FAILURE(status)) {
 		return_ACPI_STATUS(status);
+	}
+
+	/* Clear the GPE (of stale events) */
 
-	/* Clear the GPE (of stale events), then enable it */
 	status = acpi_hw_clear_gpe(gpe_event_info);
-	if (ACPI_FAILURE(status))
+	if (ACPI_FAILURE(status)) {
 		return_ACPI_STATUS(status);
+	}
 
 	/* Enable the requested GPE */
+
 	status = acpi_hw_write_gpe_enable_reg(gpe_event_info);
 	return_ACPI_STATUS(status);
 }
@@ -135,7 +161,10 @@ acpi_status acpi_ev_enable_gpe(struct acpi_gpe_event_info *gpe_event_info)
  *
  * RETURN:      Status
  *
- * DESCRIPTION: Disable a GPE based on the GPE type
+ * DESCRIPTION: Hardware-disable a GPE. Always disables the requested GPE,
+ *              regardless of the type or number of references.
+ *
+ * Note: The GPE lock should be already acquired when this function is called.
  *
  ******************************************************************************/
 
@@ -145,24 +174,71 @@ acpi_status acpi_ev_disable_gpe(struct acpi_gpe_event_info *gpe_event_info)
 
 	ACPI_FUNCTION_TRACE(ev_disable_gpe);
 
-	/* Make sure HW enable masks are updated */
+
+	/*
+	 * Note: Always disable the GPE, even if we think that that it is already
+	 * disabled. It is possible that the AML or some other code has enabled
+	 * the GPE behind our back.
+	 */
+
+	/* Ensure the HW enable masks are current */
 
 	status = acpi_ev_update_gpe_enable_masks(gpe_event_info);
-	if (ACPI_FAILURE(status))
+	if (ACPI_FAILURE(status)) {
 		return_ACPI_STATUS(status);
+	}
 
 	/*
-	 * Even if we don't know the GPE type, make sure that we always
-	 * disable it. low_disable_gpe will just clear the enable bit for this
-	 * GPE and write it. It will not write out the current GPE enable mask,
-	 * since this may inadvertently enable GPEs too early, if a rogue GPE has
-	 * come in during ACPICA initialization - possibly as a result of AML or
-	 * other code that has enabled the GPE.
+	 * Always H/W disable this GPE, even if we don't know the GPE type.
+	 * Simply clear the enable bit for this particular GPE, but do not
+	 * write out the current GPE enable mask since this may inadvertently
+	 * enable GPEs too early. An example is a rogue GPE that has arrived
+	 * during ACPICA initialization - possibly because AML or other code
+	 * has enabled the GPE.
 	 */
 	status = acpi_hw_low_disable_gpe(gpe_event_info);
 	return_ACPI_STATUS(status);
 }
 
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ev_low_get_gpe_info
+ *
+ * PARAMETERS:  gpe_number          - Raw GPE number
+ *              gpe_block           - A GPE info block
+ *
+ * RETURN:      A GPE event_info struct. NULL if not a valid GPE (The gpe_number
+ *              is not within the specified GPE block)
+ *
+ * DESCRIPTION: Returns the event_info struct associated with this GPE. This is
+ *              the low-level implementation of ev_get_gpe_event_info.
+ *
+ ******************************************************************************/
+
+struct acpi_gpe_event_info *acpi_ev_low_get_gpe_info(u32 gpe_number,
+						     struct acpi_gpe_block_info
+						     *gpe_block)
+{
+	u32 gpe_index;
+
+	/*
+	 * Validate that the gpe_number is within the specified gpe_block.
+	 * (Two steps)
+	 */
+	if (!gpe_block || (gpe_number < gpe_block->block_base_number)) {
+		return (NULL);
+	}
+
+	gpe_index = gpe_number - gpe_block->block_base_number;
+	if (gpe_index >= gpe_block->gpe_count) {
+		return (NULL);
+	}
+
+	return (&gpe_block->event_info[gpe_index]);
+}
+
+
 /*******************************************************************************
  *
  * FUNCTION:    acpi_ev_get_gpe_event_info
@@ -184,7 +260,7 @@ struct acpi_gpe_event_info *acpi_ev_get_gpe_event_info(acpi_handle gpe_device,
 						       u32 gpe_number)
 {
 	union acpi_operand_object *obj_desc;
-	struct acpi_gpe_block_info *gpe_block;
+	struct acpi_gpe_event_info *gpe_info;
 	u32 i;
 
 	ACPI_FUNCTION_ENTRY();
@@ -196,17 +272,11 @@ struct acpi_gpe_event_info *acpi_ev_get_gpe_event_info(acpi_handle gpe_device,
 		/* Examine GPE Block 0 and 1 (These blocks are permanent) */
 
 		for (i = 0; i < ACPI_MAX_GPE_BLOCKS; i++) {
-			gpe_block = acpi_gbl_gpe_fadt_blocks[i];
-			if (gpe_block) {
-				if ((gpe_number >= gpe_block->block_base_number)
-				    && (gpe_number <
-					gpe_block->block_base_number +
-					(gpe_block->register_count * 8))) {
-					return (&gpe_block->
-						event_info[gpe_number -
-							   gpe_block->
-							   block_base_number]);
-				}
+			gpe_info = acpi_ev_low_get_gpe_info(gpe_number,
+							    acpi_gbl_gpe_fadt_blocks
+							    [i]);
+			if (gpe_info) {
+				return (gpe_info);
 			}
 		}
 
@@ -223,16 +293,8 @@ struct acpi_gpe_event_info *acpi_ev_get_gpe_event_info(acpi_handle gpe_device,
 		return (NULL);
 	}
 
-	gpe_block = obj_desc->device.gpe_block;
-
-	if ((gpe_number >= gpe_block->block_base_number) &&
-	    (gpe_number <
-	     gpe_block->block_base_number + (gpe_block->register_count * 8))) {
-		return (&gpe_block->
-			event_info[gpe_number - gpe_block->block_base_number]);
-	}
-
-	return (NULL);
+	return (acpi_ev_low_get_gpe_info
+		(gpe_number, obj_desc->device.gpe_block));
 }
 
 /*******************************************************************************
@@ -389,7 +451,7 @@ static void ACPI_SYSTEM_XFACE acpi_ev_asynch_execute_gpe_method(void *context)
 		return_VOID;
 	}
 
-	/* Set the GPE flags for return to enabled state */
+	/* Update the GPE register masks for return to enabled state */
 
 	(void)acpi_ev_update_gpe_enable_masks(gpe_event_info);
 
@@ -569,15 +631,18 @@ acpi_ev_gpe_dispatch(struct acpi_gpe_event_info *gpe_event_info, u32 gpe_number)
 
 	default:
 
-		/* No handler or method to run! */
-
+		/*
+		 * No handler or method to run!
+		 * 03/2010: This case should no longer be possible. We will not allow
+		 * a GPE to be enabled if it has no handler or method.
+		 */
 		ACPI_ERROR((AE_INFO,
 			    "No handler or method for GPE[0x%2X], disabling event",
 			    gpe_number));
 
 		/*
-		 * Disable the GPE. The GPE will remain disabled until the ACPICA
-		 * Core Subsystem is restarted, or a handler is installed.
+		 * Disable the GPE. The GPE will remain disabled a handler
+		 * is installed or ACPICA is restarted.
 		 */
 		status = acpi_ev_disable_gpe(gpe_event_info);
 		if (ACPI_FAILURE(status)) {