1 files changed, 126 insertions, 83 deletions

diff --git a/drivers/misc/mei/init.c b/drivers/misc/mei/init.c
index c47fa273879e..059133d8caca 100644
--- a/drivers/misc/mei/init.c
+++ b/drivers/misc/mei/init.c
@@ -43,62 +43,13 @@ const char *mei_dev_state_str(int state)
 #undef MEI_DEV_STATE
 }
 
-/**
- * mei_start - initializes host and fw to start work.
- *
- * @dev: the device structure
- *
- * returns 0 on success, <0 on failure.
- */
-int mei_start(struct mei_device *dev)
-{
-	mutex_lock(&dev->device_lock);
-
-	/* acknowledge interrupt and stop interupts */
-	mei_clear_interrupts(dev);
-
-	mei_hw_config(dev);
-
-	dev_dbg(&dev->pdev->dev, "reset in start the mei device.\n");
-
-	mei_reset(dev, 1);
-
-	if (mei_hbm_start_wait(dev)) {
-		dev_err(&dev->pdev->dev, "HBM haven't started");
-		goto err;
-	}
-
-	if (!mei_host_is_ready(dev)) {
-		dev_err(&dev->pdev->dev, "host is not ready.\n");
-		goto err;
-	}
-
-	if (!mei_hw_is_ready(dev)) {
-		dev_err(&dev->pdev->dev, "ME is not ready.\n");
-		goto err;
-	}
-
-	if (!mei_hbm_version_is_supported(dev)) {
-		dev_dbg(&dev->pdev->dev, "MEI start failed.\n");
-		goto err;
-	}
-
-	dev_dbg(&dev->pdev->dev, "link layer has been established.\n");
-
-	mutex_unlock(&dev->device_lock);
-	return 0;
-err:
-	dev_err(&dev->pdev->dev, "link layer initialization failed.\n");
-	dev->dev_state = MEI_DEV_DISABLED;
-	mutex_unlock(&dev->device_lock);
-	return -ENODEV;
-}
-EXPORT_SYMBOL_GPL(mei_start);
 
 /**
  * mei_cancel_work. Cancel mei background jobs
  *
  * @dev: the device structure
+ *
+ * returns 0 on success or < 0 if the reset hasn't succeeded
  */
 void mei_cancel_work(struct mei_device *dev)
 {
@@ -113,21 +64,19 @@ EXPORT_SYMBOL_GPL(mei_cancel_work);
  * mei_reset - resets host and fw.
  *
  * @dev: the device structure
- * @interrupts_enabled: if interrupt should be enabled after reset.
  */
-void mei_reset(struct mei_device *dev, int interrupts_enabled)
+int mei_reset(struct mei_device *dev)
 {
-	bool unexpected;
+	enum mei_dev_state state = dev->dev_state;
+	bool interrupts_enabled;
 	int ret;
 
-	unexpected = (dev->dev_state != MEI_DEV_INITIALIZING &&
-			dev->dev_state != MEI_DEV_DISABLED &&
-			dev->dev_state != MEI_DEV_POWER_DOWN &&
-			dev->dev_state != MEI_DEV_POWER_UP);
-
-	if (unexpected)
+	if (state != MEI_DEV_INITIALIZING &&
+	    state != MEI_DEV_DISABLED &&
+	    state != MEI_DEV_POWER_DOWN &&
+	    state != MEI_DEV_POWER_UP)
 		dev_warn(&dev->pdev->dev, "unexpected reset: dev_state = %s\n",
-			 mei_dev_state_str(dev->dev_state));
+			 mei_dev_state_str(state));
 
 	/* we're already in reset, cancel the init timer
 	 * if the reset was called due the hbm protocol error
@@ -136,25 +85,23 @@ void mei_reset(struct mei_device *dev, int interrupts_enabled)
 	 */
 	mei_hbm_idle(dev);
 
-	ret = mei_hw_reset(dev, interrupts_enabled);
-	if (ret) {
-		dev_err(&dev->pdev->dev, "hw reset failed disabling the device\n");
-		interrupts_enabled = false;
-	}
+	/* enter reset flow */
+	interrupts_enabled = state != MEI_DEV_POWER_DOWN;
+	dev->dev_state = MEI_DEV_RESETTING;
 
+	ret = mei_hw_reset(dev, interrupts_enabled);
+	/* fall through and remove the sw state even if hw reset has failed */
 
-	if (dev->dev_state != MEI_DEV_INITIALIZING &&
-	    dev->dev_state != MEI_DEV_POWER_UP) {
-		if (dev->dev_state != MEI_DEV_DISABLED &&
-		    dev->dev_state != MEI_DEV_POWER_DOWN)
-			dev->dev_state = MEI_DEV_RESETTING;
+	/* no need to clean up software state in case of power up */
+	if (state != MEI_DEV_INITIALIZING &&
+	    state != MEI_DEV_POWER_UP) {
 
 		/* remove all waiting requests */
 		mei_cl_all_write_clear(dev);
 
 		mei_cl_all_disconnect(dev);
 
-		/* wake up all readings so they can be interrupted */
+		/* wake up all readers and writers so they can be interrupted */
 		mei_cl_all_wakeup(dev);
 
 		/* remove entry if already in list */
@@ -170,33 +117,126 @@ void mei_reset(struct mei_device *dev, int interrupts_enabled)
 	dev->rd_msg_hdr = 0;
 	dev->wd_pending = false;
 
-	if (!interrupts_enabled) {
-		dev_dbg(&dev->pdev->dev, "intr not enabled end of reset\n");
+	if (ret) {
+		dev_err(&dev->pdev->dev, "hw_reset failed ret = %d\n", ret);
 		dev->dev_state = MEI_DEV_DISABLED;
-		return;
+		return ret;
+	}
+
+	if (state == MEI_DEV_POWER_DOWN) {
+		dev_dbg(&dev->pdev->dev, "powering down: end of reset\n");
+		dev->dev_state = MEI_DEV_DISABLED;
+		return 0;
 	}
 
 	ret = mei_hw_start(dev);
 	if (ret) {
-		dev_err(&dev->pdev->dev, "hw_start failed disabling the device\n");
+		dev_err(&dev->pdev->dev, "hw_start failed ret = %d\n", ret);
 		dev->dev_state = MEI_DEV_DISABLED;
-		return;
+		return ret;
 	}
 
 	dev_dbg(&dev->pdev->dev, "link is established start sending messages.\n");
-	/* link is established * start sending messages.  */
 
 	dev->dev_state = MEI_DEV_INIT_CLIENTS;
-
 	ret = mei_hbm_start_req(dev);
 	if (ret) {
-		dev_err(&dev->pdev->dev, "hbm_start failed disabling the device\n");
+		dev_err(&dev->pdev->dev, "hbm_start failed ret = %d\n", ret);
 		dev->dev_state = MEI_DEV_DISABLED;
-		return;
+		return ret;
 	}
+
+	return 0;
 }
 EXPORT_SYMBOL_GPL(mei_reset);
 
+/**
+ * mei_start - initializes host and fw to start work.
+ *
+ * @dev: the device structure
+ *
+ * returns 0 on success, <0 on failure.
+ */
+int mei_start(struct mei_device *dev)
+{
+	mutex_lock(&dev->device_lock);
+
+	/* acknowledge interrupt and stop interrupts */
+	mei_clear_interrupts(dev);
+
+	mei_hw_config(dev);
+
+	dev_dbg(&dev->pdev->dev, "reset in start the mei device.\n");
+
+	dev->dev_state = MEI_DEV_INITIALIZING;
+	mei_reset(dev);
+
+	if (dev->dev_state == MEI_DEV_DISABLED) {
+		dev_err(&dev->pdev->dev, "reset failed");
+		goto err;
+	}
+
+	if (mei_hbm_start_wait(dev)) {
+		dev_err(&dev->pdev->dev, "HBM haven't started");
+		goto err;
+	}
+
+	if (!mei_host_is_ready(dev)) {
+		dev_err(&dev->pdev->dev, "host is not ready.\n");
+		goto err;
+	}
+
+	if (!mei_hw_is_ready(dev)) {
+		dev_err(&dev->pdev->dev, "ME is not ready.\n");
+		goto err;
+	}
+
+	if (!mei_hbm_version_is_supported(dev)) {
+		dev_dbg(&dev->pdev->dev, "MEI start failed.\n");
+		goto err;
+	}
+
+	dev_dbg(&dev->pdev->dev, "link layer has been established.\n");
+
+	mutex_unlock(&dev->device_lock);
+	return 0;
+err:
+	dev_err(&dev->pdev->dev, "link layer initialization failed.\n");
+	dev->dev_state = MEI_DEV_DISABLED;
+	mutex_unlock(&dev->device_lock);
+	return -ENODEV;
+}
+EXPORT_SYMBOL_GPL(mei_start);
+
+/**
+ * mei_restart - restart device after suspend
+ *
+ * @dev: the device structure
+ *
+ * returns 0 on success or -ENODEV if the restart hasn't succeeded
+ */
+int mei_restart(struct mei_device *dev)
+{
+	int err;
+
+	mutex_lock(&dev->device_lock);
+
+	mei_clear_interrupts(dev);
+
+	dev->dev_state = MEI_DEV_POWER_UP;
+
+	err = mei_reset(dev);
+
+	mutex_unlock(&dev->device_lock);
+
+	if (err || dev->dev_state == MEI_DEV_DISABLED)
+		return -ENODEV;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(mei_restart);
+
+
 static void mei_reset_work(struct work_struct *work)
 {
 	struct mei_device *dev =
@@ -204,9 +244,12 @@ static void mei_reset_work(struct work_struct *work)
 
 	mutex_lock(&dev->device_lock);
 
-	mei_reset(dev, true);
+	mei_reset(dev);
 
 	mutex_unlock(&dev->device_lock);
+
+	if (dev->dev_state == MEI_DEV_DISABLED)
+		dev_err(&dev->pdev->dev, "reset failed");
 }
 
 void mei_stop(struct mei_device *dev)
@@ -222,7 +265,7 @@ void mei_stop(struct mei_device *dev)
 	mei_wd_stop(dev);
 
 	dev->dev_state = MEI_DEV_POWER_DOWN;
-	mei_reset(dev, 0);
+	mei_reset(dev);
 
 	mutex_unlock(&dev->device_lock);