ACPICA: Implicit notify support

This feature provides an automatic device notification for wake devices
when a wakeup GPE occurs and there is no corresponding GPE method or
handler. Rather than ignoring such a GPE, an implicit AML Notify
operation is performed on the parent device object.
This feature is not part of the ACPI specification and is provided for
Windows compatibility only.

Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 100 insertions, 72 deletions

diff --git a/drivers/acpi/acpica/evgpe.c b/drivers/acpi/acpica/evgpe.c
index c25999546c8..2dbca95979c 100644
--- a/drivers/acpi/acpica/evgpe.c
+++ b/drivers/acpi/acpica/evgpe.c
@@ -115,12 +115,13 @@ acpi_ev_enable_gpe(struct acpi_gpe_event_info *gpe_event_info)
 	ACPI_FUNCTION_TRACE(ev_enable_gpe);
 
 	/*
-	 * 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.
+	 * We will only allow a GPE to be enabled if it has either an associated
+	 * method (_Lxx/_Exx) or a handler, or is using the implicit notify
+	 * feature. 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)) {
+	if ((gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) ==
+	    ACPI_GPE_DISPATCH_NONE) {
 		return_ACPI_STATUS(AE_NO_HANDLER);
 	}
 
@@ -486,12 +487,26 @@ static void ACPI_SYSTEM_XFACE acpi_ev_asynch_execute_gpe_method(void *context)
 		return_VOID;
 	}
 
-	/*
-	 * Must check for control method type dispatch one more time to avoid a
-	 * race with ev_gpe_install_handler
-	 */
-	if ((local_gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) ==
-	    ACPI_GPE_DISPATCH_METHOD) {
+	/* Do the correct dispatch - normal method or implicit notify */
+
+	switch (local_gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) {
+	case ACPI_GPE_DISPATCH_NOTIFY:
+
+		/*
+		 * Implicit notify.
+		 * Dispatch a DEVICE_WAKE notify to the appropriate handler.
+		 * NOTE: the request is queued for execution after this method
+		 * completes. The notify handlers are NOT invoked synchronously
+		 * from this thread -- because handlers may in turn run other
+		 * control methods.
+		 */
+		status =
+		    acpi_ev_queue_notify_request(local_gpe_event_info->dispatch.
+						 device_node,
+						 ACPI_NOTIFY_DEVICE_WAKE);
+		break;
+
+	case ACPI_GPE_DISPATCH_METHOD:
 
 		/* Allocate the evaluation information block */
 
@@ -518,6 +533,11 @@ static void ACPI_SYSTEM_XFACE acpi_ev_asynch_execute_gpe_method(void *context)
 					(local_gpe_event_info->dispatch.
 					 method_node)));
 		}
+
+		break;
+
+	default:
+		return_VOID;    /* Should never happen */
 	}
 
 	/* Defer enabling of GPE until all notify handlers are done */
@@ -531,6 +551,7 @@ static void ACPI_SYSTEM_XFACE acpi_ev_asynch_execute_gpe_method(void *context)
 	return_VOID;
 }
 
+
 /*******************************************************************************
  *
  * FUNCTION:    acpi_ev_asynch_enable_gpe
@@ -541,38 +562,60 @@ static void ACPI_SYSTEM_XFACE acpi_ev_asynch_execute_gpe_method(void *context)
  * RETURN:      None
  *
  * DESCRIPTION: Asynchronous clear/enable for GPE. This allows the GPE to
- *              complete.
+ *              complete (i.e., finish execution of Notify)
  *
  ******************************************************************************/
 
 static void ACPI_SYSTEM_XFACE acpi_ev_asynch_enable_gpe(void *context)
 {
 	struct acpi_gpe_event_info *gpe_event_info = context;
+
+	(void)acpi_ev_finish_gpe(gpe_event_info);
+
+	ACPI_FREE(gpe_event_info);
+	return;
+}
+
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ev_finish_gpe
+ *
+ * PARAMETERS:  gpe_event_info      - Info for this GPE
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Clear/Enable a GPE. Common code that is used after execution
+ *              of a GPE method or a synchronous or asynchronous GPE handler.
+ *
+ ******************************************************************************/
+
+acpi_status acpi_ev_finish_gpe(struct acpi_gpe_event_info *gpe_event_info)
+{
 	acpi_status status;
 
 	if ((gpe_event_info->flags & ACPI_GPE_XRUPT_TYPE_MASK) ==
 	    ACPI_GPE_LEVEL_TRIGGERED) {
 		/*
-		 * GPE is level-triggered, we clear the GPE status bit after handling
-		 * the event.
+		 * GPE is level-triggered, we clear the GPE status bit after
+		 * handling the event.
 		 */
 		status = acpi_hw_clear_gpe(gpe_event_info);
 		if (ACPI_FAILURE(status)) {
-			goto exit;
+			return (status);
 		}
 	}
 
 	/*
-	 * Enable this GPE, conditionally. This means that the GPE will only be
-	 * physically enabled if the enable_for_run bit is set in the event_info
+	 * Enable this GPE, conditionally. This means that the GPE will
+	 * only be physically enabled if the enable_for_run bit is set
+	 * in the event_info.
 	 */
 	(void)acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_CONDITIONAL_ENABLE);
-
-exit:
-	ACPI_FREE(gpe_event_info);
-	return;
+	return (AE_OK);
 }
 
+
 /*******************************************************************************
  *
  * FUNCTION:    acpi_ev_gpe_dispatch
@@ -595,6 +638,7 @@ acpi_ev_gpe_dispatch(struct acpi_namespace_node *gpe_device,
 		    struct acpi_gpe_event_info *gpe_event_info, u32 gpe_number)
 {
 	acpi_status status;
+	u32 return_value;
 
 	ACPI_FUNCTION_TRACE(ev_gpe_dispatch);
 
@@ -616,54 +660,49 @@ acpi_ev_gpe_dispatch(struct acpi_namespace_node *gpe_device,
 	}
 
 	/*
-	 * Dispatch the GPE to either an installed handler, or the control method
-	 * associated with this GPE (_Lxx or _Exx). If a handler exists, we invoke
-	 * it and do not attempt to run the method. If there is neither a handler
-	 * nor a method, we disable this GPE to prevent further such pointless
-	 * events from firing.
+	 * Always disable the GPE so that it does not keep firing before
+	 * any asynchronous activity completes (either from the execution
+	 * of a GPE method or an asynchronous GPE handler.)
+	 *
+	 * If there is no handler or method to run, just disable the
+	 * GPE and leave it disabled permanently to prevent further such
+	 * pointless events from firing.
+	 */
+	status = acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_DISABLE);
+	if (ACPI_FAILURE(status)) {
+		ACPI_EXCEPTION((AE_INFO, status,
+				"Unable to disable GPE%02X", gpe_number));
+		return_UINT32(ACPI_INTERRUPT_NOT_HANDLED);
+	}
+
+	/*
+	 * Dispatch the GPE to either an installed handler or the control
+	 * method associated with this GPE (_Lxx or _Exx). If a handler
+	 * exists, we invoke it and do not attempt to run the method.
+	 * If there is neither a handler nor a method, leave the GPE
+	 * disabled.
 	 */
 	switch (gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) {
 	case ACPI_GPE_DISPATCH_HANDLER:
 
-		/*
-		 * Invoke the installed handler (at interrupt level)
-		 * Ignore return status for now.
-		 * TBD: leave GPE disabled on error?
-		 */
-		(void)gpe_event_info->dispatch.handler->address(gpe_device,
-								gpe_number,
-								gpe_event_info->
-								dispatch.
-								handler->
-								context);
-
-		/* It is now safe to clear level-triggered events. */
-
-		if ((gpe_event_info->flags & ACPI_GPE_XRUPT_TYPE_MASK) ==
-		    ACPI_GPE_LEVEL_TRIGGERED) {
-			status = acpi_hw_clear_gpe(gpe_event_info);
-			if (ACPI_FAILURE(status)) {
-				ACPI_EXCEPTION((AE_INFO, status,
-					"Unable to clear GPE[0x%2X]",
-						gpe_number));
-				return_UINT32(ACPI_INTERRUPT_NOT_HANDLED);
-			}
+		/* Invoke the installed handler (at interrupt level) */
+
+		return_value =
+		    gpe_event_info->dispatch.handler->address(gpe_device,
+							      gpe_number,
+							      gpe_event_info->
+							      dispatch.handler->
+							      context);
+
+		/* If requested, clear (if level-triggered) and reenable the GPE */
+
+		if (return_value & ACPI_REENABLE_GPE) {
+			(void)acpi_ev_finish_gpe(gpe_event_info);
 		}
 		break;
 
 	case ACPI_GPE_DISPATCH_METHOD:
-
-		/*
-		 * Disable the GPE, so it doesn't keep firing before the method has a
-		 * chance to run (it runs asynchronously with interrupts enabled).
-		 */
-		status = acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_DISABLE);
-		if (ACPI_FAILURE(status)) {
-			ACPI_EXCEPTION((AE_INFO, status,
-					"Unable to disable GPE[0x%2X]",
-					gpe_number));
-			return_UINT32(ACPI_INTERRUPT_NOT_HANDLED);
-		}
+	case ACPI_GPE_DISPATCH_NOTIFY:
 
 		/*
 		 * Execute the method associated with the GPE
@@ -690,17 +729,6 @@ acpi_ev_gpe_dispatch(struct acpi_namespace_node *gpe_device,
 			    "No handler or method for GPE[0x%2X], disabling event",
 			    gpe_number));
 
-		/*
-		 * Disable the GPE. The GPE will remain disabled a handler
-		 * is installed or ACPICA is restarted.
-		 */
-		status = acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_DISABLE);
-		if (ACPI_FAILURE(status)) {
-			ACPI_EXCEPTION((AE_INFO, status,
-					"Unable to disable GPE[0x%2X]",
-					gpe_number));
-			return_UINT32(ACPI_INTERRUPT_NOT_HANDLED);
-		}
 		break;
 	}