[PATCH v2 3/3] cros_ec: Don't signal wake event for non-wake host events

[Thierry Escande]

From: Shawn Nematbakhsh <shawnn@xxxxxxxxxxxx>

The subset of wake-enabled host events is defined by the EC, but the EC
may still send non-wake host events if we're in the process of
suspending. Get the mask of wake-enabled host events from the EC and
filter out non-wake events to prevent spurious aborted suspend
attempts.

Signed-off-by: Shawn Nematbakhsh <shawnn@xxxxxxxxxxxx>
Signed-off-by: Thierry Escande <thierry.escande@xxxxxxxxxxxxx>
---
 drivers/mfd/cros_ec.c                   | 13 ++++--
 drivers/platform/chrome/cros_ec_proto.c | 76 ++++++++++++++++++++++++++++++---
 include/linux/mfd/cros_ec.h             |  5 ++-
 3 files changed, 85 insertions(+), 9 deletions(-)

diff --git a/drivers/mfd/cros_ec.c b/drivers/mfd/cros_ec.c
index 9b66a98..1bcb502 100644
--- a/drivers/mfd/cros_ec.c
+++ b/drivers/mfd/cros_ec.c
@@ -54,12 +54,19 @@ static const struct mfd_cell ec_pd_cell = {
 static irqreturn_t ec_irq_thread(int irq, void *data)
 {
 	struct cros_ec_device *ec_dev = data;
+	bool wake_event = true;
 	int ret;
 
-	if (device_may_wakeup(ec_dev->dev))
+	ret = cros_ec_get_next_event(ec_dev, &wake_event);
+
+	/*
+	 * Signal only if wake host events or any interrupt if
+	 * cros_ec_get_next_event() returned an error (default value for
+	 * wake_event is true)
+	 */
+	if (wake_event && device_may_wakeup(ec_dev->dev))
 		pm_wakeup_event(ec_dev->dev, 0);
 
-	ret = cros_ec_get_next_event(ec_dev);
 	if (ret > 0)
 		blocking_notifier_call_chain(&ec_dev->event_notifier,
 					     0, ec_dev);
@@ -212,7 +219,7 @@ EXPORT_SYMBOL(cros_ec_suspend);
 
 static void cros_ec_drain_events(struct cros_ec_device *ec_dev)
 {
-	while (cros_ec_get_next_event(ec_dev) > 0)
+	while (cros_ec_get_next_event(ec_dev, NULL) > 0)
 		blocking_notifier_call_chain(&ec_dev->event_notifier,
 					     1, ec_dev);
 }
diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
index d6942a6..8dfa7fc 100644
--- a/drivers/platform/chrome/cros_ec_proto.c
+++ b/drivers/platform/chrome/cros_ec_proto.c
@@ -150,6 +150,40 @@ int cros_ec_check_result(struct cros_ec_device *ec_dev,
 }
 EXPORT_SYMBOL(cros_ec_check_result);
 
+/*
+ * cros_ec_get_host_event_wake_mask
+ *
+ * Get the mask of host events that cause wake from suspend.
+ *
+ * @ec_dev: EC device to call
+ * @msg: message structure to use
+ * @mask: result when function returns >=0.
+ *
+ * LOCKING:
+ * the caller has ec_dev->lock mutex, or the caller knows there is
+ * no other command in progress.
+ */
+static int cros_ec_get_host_event_wake_mask(struct cros_ec_device *ec_dev,
+					    struct cros_ec_command *msg,
+					    uint32_t *mask)
+{
+	struct ec_response_host_event_mask *r;
+	int ret;
+
+	msg->command = EC_CMD_HOST_EVENT_GET_WAKE_MASK;
+	msg->version = 0;
+	msg->outsize = 0;
+	msg->insize = sizeof(*r);
+
+	ret = send_command(ec_dev, msg);
+	if (ret > 0) {
+		r = (struct ec_response_host_event_mask *)msg->data;
+		*mask = r->mask;
+	}
+
+	return ret;
+}
+
 static int cros_ec_host_command_proto_query(struct cros_ec_device *ec_dev,
 					    int devidx,
 					    struct cros_ec_command *msg)
@@ -387,6 +421,15 @@ int cros_ec_query_all(struct cros_ec_device *ec_dev)
 	else
 		ec_dev->mkbp_event_supported = 1;
 
+	/*
+	 * Get host event wake mask, assume all events are wake events
+	 * if unavailable.
+	 */
+	ret = cros_ec_get_host_event_wake_mask(ec_dev, proto_msg,
+					       &ec_dev->host_event_wake_mask);
+	if (ret < 0)
+		ec_dev->host_event_wake_mask = U32_MAX;
+
 	ret = 0;
 
 exit:
@@ -504,12 +547,35 @@ static int get_keyboard_state_event(struct cros_ec_device *ec_dev)
 	return ec_dev->event_size;
 }
 
-int cros_ec_get_next_event(struct cros_ec_device *ec_dev)
+int cros_ec_get_next_event(struct cros_ec_device *ec_dev, bool *wake_event)
 {
-	if (ec_dev->mkbp_event_supported)
-		return get_next_event(ec_dev);
-	else
-		return get_keyboard_state_event(ec_dev);
+	u32 host_event;
+	int ret;
+
+	if (!ec_dev->mkbp_event_supported) {
+		ret = get_keyboard_state_event(ec_dev);
+		if (ret < 0)
+			return ret;
+
+		if (wake_event)
+			*wake_event = true;
+
+		return ret;
+	}
+
+	ret = get_next_event(ec_dev);
+	if (ret < 0)
+		return ret;
+
+	if (wake_event) {
+		host_event = cros_ec_get_host_event(ec_dev);
+
+		/* Consider non-host_event as wake event */
+		*wake_event = !host_event ||
+			      !!(host_event & ec_dev->host_event_wake_mask);
+	}
+
+	return ret;
 }
 EXPORT_SYMBOL(cros_ec_get_next_event);
 
diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
index 2ceb245..bb85325 100644
--- a/include/linux/mfd/cros_ec.h
+++ b/include/linux/mfd/cros_ec.h
@@ -148,6 +148,7 @@ struct cros_ec_device {
 
 	struct ec_response_get_next_event event_data;
 	int event_size;
+	u32 host_event_wake_mask;
 };
 
 /**
@@ -294,10 +295,12 @@ int cros_ec_query_all(struct cros_ec_device *ec_dev);
  * cros_ec_get_next_event -  Fetch next event from the ChromeOS EC
  *
  * @ec_dev: Device to fetch event from
+ * @wake_event: Pointer to a bool set to true upon return if the event might be
+ *              treated as a wake event. Ignored if null.
  *
  * Returns: 0 on success, Linux error number on failure
  */
-int cros_ec_get_next_event(struct cros_ec_device *ec_dev);
+int cros_ec_get_next_event(struct cros_ec_device *ec_dev, bool *wake_event);
 
 /**
  * cros_ec_get_host_event - Return a mask of event set by the EC.
-- 
2.7.4