From fd247447c1d94a79d5cfc647430784306b3a8323 Mon Sep 17 00:00:00 2001
From: Rafael J. Wysocki <rjw@sisk.pl>
Date: Tue, 8 Jun 2010 10:49:08 +0200
Subject: [PATCH] ACPI / ACPICA: Fix low-level GPE manipulation code

ACPICA uses acpi_ev_enable_gpe() for enabling GPEs at the low level,
which is incorrect, because this function only enables the GPE if the
corresponding bit in its enable register's enable_for_run mask is set.
This causes acpi_set_gpe() to work incorrectly if used for enabling
GPEs that were not previously enabled with acpi_enable_gpe().  As a
result, among other things, wakeup-only GPEs are never enabled by
acpi_enable_wakeup_device(), so the devices that use them are unable
to wake up the system.

To fix this issue remove acpi_ev_enable_gpe() and its counterpart
acpi_ev_disable_gpe() and replace acpi_hw_low_disable_gpe() with
acpi_hw_low_set_gpe() that will be used instead to manipulate GPE
enable bits at the low level.  Make the users of acpi_ev_enable_gpe()
and acpi_ev_disable_gpe() call acpi_hw_low_set_gpe() instead and
make sure that GPE enable masks are only updated by acpi_enable_gpe()
and acpi_disable_gpe() when GPE reference counters change from 0
to 1 and from 1 to 0, respectively.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
---
 drivers/acpi/acpica/acevents.h |    4 --
 drivers/acpi/acpica/achware.h  |    3 +
 drivers/acpi/acpica/evgpe.c    |   78 +----------------------------------------
 drivers/acpi/acpica/evxfevnt.c |   66 ++++++++++++++++++++++++++++++----
 drivers/acpi/acpica/hwgpe.c    |   26 +++++++++++--
 include/acpi/acexcep.h         |    2 -
 6 files changed, 84 insertions(+), 95 deletions(-)

Index: linux-2.6-stable/drivers/acpi/acpica/acevents.h
===================================================================
--- linux-2.6-stable.orig/drivers/acpi/acpica/acevents.h
+++ linux-2.6-stable/drivers/acpi/acpica/acevents.h
@@ -78,10 +78,6 @@ acpi_ev_queue_notify_request(struct acpi
 acpi_status
 acpi_ev_update_gpe_enable_masks(struct acpi_gpe_event_info *gpe_event_info);
 
-acpi_status acpi_ev_enable_gpe(struct acpi_gpe_event_info *gpe_event_info);
-
-acpi_status acpi_ev_disable_gpe(struct acpi_gpe_event_info *gpe_event_info);
-
 struct acpi_gpe_event_info *acpi_ev_get_gpe_event_info(acpi_handle gpe_device,
 						       u32 gpe_number);
 
Index: linux-2.6-stable/drivers/acpi/acpica/achware.h
===================================================================
--- linux-2.6-stable.orig/drivers/acpi/acpica/achware.h
+++ linux-2.6-stable/drivers/acpi/acpica/achware.h
@@ -93,7 +93,8 @@ acpi_status acpi_hw_write_port(acpi_io_a
 u32 acpi_hw_gpe_register_bit(struct acpi_gpe_event_info *gpe_event_info,
 			     struct acpi_gpe_register_info *gpe_register_info);
 
-acpi_status acpi_hw_low_disable_gpe(struct acpi_gpe_event_info *gpe_event_info);
+acpi_status
+acpi_hw_low_set_gpe(struct acpi_gpe_event_info *gpe_event_info, u8 action);
 
 acpi_status
 acpi_hw_write_gpe_enable_reg(struct acpi_gpe_event_info *gpe_event_info);
Index: linux-2.6-stable/drivers/acpi/acpica/evgpe.c
===================================================================
--- linux-2.6-stable.orig/drivers/acpi/acpica/evgpe.c
+++ linux-2.6-stable/drivers/acpi/acpica/evgpe.c
@@ -94,76 +94,6 @@ acpi_ev_update_gpe_enable_masks(struct a
 
 /*******************************************************************************
  *
- * FUNCTION:    acpi_ev_enable_gpe
- *
- * PARAMETERS:  gpe_event_info          - GPE to enable
- *
- * RETURN:      Status
- *
- * DESCRIPTION: Enable a GPE based on the GPE type
- *
- ******************************************************************************/
-
-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 */
-
-	status = acpi_ev_update_gpe_enable_masks(gpe_event_info);
-	if (ACPI_FAILURE(status))
-		return_ACPI_STATUS(status);
-
-	/* Clear the GPE (of stale events), then enable it */
-	status = acpi_hw_clear_gpe(gpe_event_info);
-	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);
-}
-
-/*******************************************************************************
- *
- * FUNCTION:    acpi_ev_disable_gpe
- *
- * PARAMETERS:  gpe_event_info          - GPE to disable
- *
- * RETURN:      Status
- *
- * DESCRIPTION: Disable a GPE based on the GPE type
- *
- ******************************************************************************/
-
-acpi_status acpi_ev_disable_gpe(struct acpi_gpe_event_info *gpe_event_info)
-{
-	acpi_status status;
-
-	ACPI_FUNCTION_TRACE(ev_disable_gpe);
-
-	/* Make sure HW enable masks are updated */
-
-	status = acpi_ev_update_gpe_enable_masks(gpe_event_info);
-	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.
-	 */
-	status = acpi_hw_low_disable_gpe(gpe_event_info);
-	return_ACPI_STATUS(status);
-}
-
-/*******************************************************************************
- *
  * FUNCTION:    acpi_ev_get_gpe_event_info
  *
  * PARAMETERS:  gpe_device          - Device node. NULL for GPE0/GPE1
@@ -388,10 +318,6 @@ static void ACPI_SYSTEM_XFACE acpi_ev_as
 		return_VOID;
 	}
 
-	/* Set the GPE flags for return to enabled state */
-
-	(void)acpi_ev_update_gpe_enable_masks(gpe_event_info);
-
 	/*
 	 * Take a snapshot of the GPE info for this level - we copy the info to
 	 * prevent a race condition with remove_handler/remove_block.
@@ -544,7 +470,7 @@ acpi_ev_gpe_dispatch(struct acpi_gpe_eve
 		 * 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_ev_disable_gpe(gpe_event_info);
+		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[%2X]",
@@ -578,7 +504,7 @@ acpi_ev_gpe_dispatch(struct acpi_gpe_eve
 		 * Disable the GPE. The GPE will remain disabled until the ACPICA
 		 * Core Subsystem is restarted, or a handler is installed.
 		 */
-		status = acpi_ev_disable_gpe(gpe_event_info);
+		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[%2X]",
Index: linux-2.6-stable/drivers/acpi/acpica/evxfevnt.c
===================================================================
--- linux-2.6-stable.orig/drivers/acpi/acpica/evxfevnt.c
+++ linux-2.6-stable/drivers/acpi/acpica/evxfevnt.c
@@ -201,6 +201,44 @@ ACPI_EXPORT_SYMBOL(acpi_enable_event)
 
 /*******************************************************************************
  *
+ * FUNCTION:    acpi_clear_and_enable_gpe
+ *
+ * PARAMETERS:  gpe_event_info  - GPE to enable
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Clear the given GPE from stale events and enable it.
+ *
+ ******************************************************************************/
+static acpi_status
+acpi_clear_and_enable_gpe(struct acpi_gpe_event_info *gpe_event_info)
+{
+	acpi_status status;
+
+	/*
+	 * 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);
+	}
+
+	/* Clear the GPE (of stale events) */
+	status = acpi_hw_clear_gpe(gpe_event_info);
+	if (ACPI_FAILURE(status)) {
+		return_ACPI_STATUS(status);
+	}
+
+	/* Enable the requested GPE */
+	status = acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_ENABLE);
+
+	return_ACPI_STATUS(status);
+}
+
+/*******************************************************************************
+ *
  * FUNCTION:    acpi_set_gpe
  *
  * PARAMETERS:  gpe_device      - Parent GPE Device
@@ -235,11 +273,11 @@ acpi_status acpi_set_gpe(acpi_handle gpe
 
 	switch (action) {
 	case ACPI_GPE_ENABLE:
-		status = acpi_ev_enable_gpe(gpe_event_info);
+		status = acpi_clear_and_enable_gpe(gpe_event_info);
 		break;
 
 	case ACPI_GPE_DISABLE:
-		status = acpi_ev_disable_gpe(gpe_event_info);
+		status = acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_DISABLE);
 		break;
 
 	default:
@@ -291,9 +329,13 @@ acpi_status acpi_enable_gpe(acpi_handle 
 
 	if (type & ACPI_GPE_TYPE_RUNTIME) {
 		if (++gpe_event_info->runtime_count == 1) {
-			status = acpi_ev_enable_gpe(gpe_event_info);
-			if (ACPI_FAILURE(status))
+			status = acpi_ev_update_gpe_enable_masks(gpe_event_info);
+			if (ACPI_SUCCESS(status)) {
+				status = acpi_clear_and_enable_gpe(gpe_event_info);
+			}
+			if (ACPI_FAILURE(status)) {
 				gpe_event_info->runtime_count--;
+			}
 		}
 	}
 
@@ -308,7 +350,7 @@ acpi_status acpi_enable_gpe(acpi_handle 
 		 * system into a sleep state.
 		 */
 		if (++gpe_event_info->wakeup_count == 1)
-			acpi_ev_update_gpe_enable_masks(gpe_event_info);
+			status = acpi_ev_update_gpe_enable_masks(gpe_event_info);
 	}
 
 unlock_and_exit:
@@ -351,8 +393,16 @@ acpi_status acpi_disable_gpe(acpi_handle
 	}
 
 	if ((type & ACPI_GPE_TYPE_RUNTIME) && gpe_event_info->runtime_count) {
-		if (--gpe_event_info->runtime_count == 0)
-			status = acpi_ev_disable_gpe(gpe_event_info);
+		if (--gpe_event_info->runtime_count == 0) {
+			status = acpi_ev_update_gpe_enable_masks(gpe_event_info);
+			if (ACPI_SUCCESS(status)) {
+				status = acpi_hw_low_set_gpe(gpe_event_info,
+							     ACPI_GPE_DISABLE);
+			}
+			if (ACPI_FAILURE(status)) {
+				gpe_event_info->runtime_count++;
+			}
+		}
 	}
 
 	if ((type & ACPI_GPE_TYPE_WAKE) && gpe_event_info->wakeup_count) {
@@ -361,7 +411,7 @@ acpi_status acpi_disable_gpe(acpi_handle
 		 * states, so we don't need to disable them here.
 		 */
 		if (--gpe_event_info->wakeup_count == 0)
-			acpi_ev_update_gpe_enable_masks(gpe_event_info);
+			status = acpi_ev_update_gpe_enable_masks(gpe_event_info);
 	}
 
 unlock_and_exit:
Index: linux-2.6-stable/drivers/acpi/acpica/hwgpe.c
===================================================================
--- linux-2.6-stable.orig/drivers/acpi/acpica/hwgpe.c
+++ linux-2.6-stable/drivers/acpi/acpica/hwgpe.c
@@ -78,23 +78,27 @@ u32 acpi_hw_gpe_register_bit(struct acpi
 
 /******************************************************************************
  *
- * FUNCTION:	acpi_hw_low_disable_gpe
+ * FUNCTION:	acpi_hw_low_set_gpe
  *
  * PARAMETERS:	gpe_event_info	    - Info block for the GPE to be disabled
+ *		action		    - Enable or disable
  *
  * RETURN:	Status
  *
- * DESCRIPTION: Disable a single GPE in the enable register.
+ * DESCRIPTION: Enable or disable a single GPE in its enable register.
  *
  ******************************************************************************/
 
-acpi_status acpi_hw_low_disable_gpe(struct acpi_gpe_event_info *gpe_event_info)
+acpi_status
+acpi_hw_low_set_gpe(struct acpi_gpe_event_info *gpe_event_info, u8 action)
 {
 	struct acpi_gpe_register_info *gpe_register_info;
 	acpi_status status;
 	u32 enable_mask;
 	u32 register_bit;
 
+	ACPI_FUNCTION_ENTRY();
+
 	/* Get the info block for the entire GPE register */
 
 	gpe_register_info = gpe_event_info->register_info;
@@ -109,11 +113,23 @@ acpi_status acpi_hw_low_disable_gpe(stru
 		return (status);
 	}
 
-	/* Clear just the bit that corresponds to this GPE */
+	/* Set or clear just the bit that corresponds to this GPE */
 
 	register_bit = acpi_hw_gpe_register_bit(gpe_event_info,
 						gpe_register_info);
-	ACPI_CLEAR_BIT(enable_mask, register_bit);
+	switch (action) {
+	case ACPI_GPE_ENABLE:
+		ACPI_SET_BIT(enable_mask, register_bit);
+		break;
+
+	case ACPI_GPE_DISABLE:
+		ACPI_CLEAR_BIT(enable_mask, register_bit);
+		break;
+
+	default:
+		ACPI_ERROR((AE_INFO, "Invalid action\n"));
+		return (AE_BAD_PARAMETER);
+	}
 
 	/* Write the updated enable mask */
 
Index: linux-2.6-stable/include/acpi/acexcep.h
===================================================================
--- linux-2.6-stable.orig/include/acpi/acexcep.h
+++ linux-2.6-stable/include/acpi/acexcep.h
@@ -87,7 +87,7 @@
 #define AE_NO_GLOBAL_LOCK               (acpi_status) (0x0017 | AE_CODE_ENVIRONMENTAL)
 #define AE_ABORT_METHOD                 (acpi_status) (0x0018 | AE_CODE_ENVIRONMENTAL)
 #define AE_SAME_HANDLER                 (acpi_status) (0x0019 | AE_CODE_ENVIRONMENTAL)
-#define AE_WAKE_ONLY_GPE                (acpi_status) (0x001A | AE_CODE_ENVIRONMENTAL)
+#define AE_NO_HANDLER                   (acpi_status) (0x001A | AE_CODE_ENVIRONMENTAL)
 #define AE_OWNER_ID_LIMIT               (acpi_status) (0x001B | AE_CODE_ENVIRONMENTAL)
 
 #define AE_CODE_ENV_MAX                 0x001B
