mei: check if the hardware reset succeeded

The hw may have multiple steps for resetting
so we need to check if it has really succeeded.
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/mei/hw-me.c

@@ -171,7 +171,7 @@ static void mei_me_hw_reset_release(struct mei_device *dev)
  * @dev: the device structure
  * @intr_enable: if interrupt should be enabled after reset.
  */
-static void mei_me_hw_reset(struct mei_device *dev, bool intr_enable)
+static int mei_me_hw_reset(struct mei_device *dev, bool intr_enable)
 {
 	struct mei_me_hw *hw = to_me_hw(dev);
 	u32 hcsr = mei_hcsr_read(hw);
@@ -191,6 +191,7 @@ static void mei_me_hw_reset(struct mei_device *dev, bool intr_enable)
 		mei_me_hw_reset_release(dev);
 
 	dev_dbg(&dev->pdev->dev, "current HCSR = 0x%08x.\n", mei_hcsr_read(hw));
+	return 0;
 }
 
 /**

drivers/misc/mei/init.c

@@ -132,13 +132,19 @@ EXPORT_SYMBOL_GPL(mei_start);
 void mei_reset(struct mei_device *dev, int interrupts_enabled)
 {
 	bool unexpected;
+	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);
 
-	mei_hw_reset(dev, interrupts_enabled);
+	ret = mei_hw_reset(dev, interrupts_enabled);
+	if (ret) {
+		dev_err(&dev->pdev->dev, "hw reset failed disabling the device\n");
+		interrupts_enabled = false;
+		dev->dev_state = MEI_DEV_DISABLED;
+	}
 
 	dev->hbm_state = MEI_HBM_IDLE;
 

drivers/misc/mei/mei_dev.h

@@ -233,7 +233,7 @@ struct mei_hw_ops {
 	bool (*host_is_ready) (struct mei_device *dev);
 
 	bool (*hw_is_ready) (struct mei_device *dev);
-	void (*hw_reset) (struct mei_device *dev, bool enable);
+	int (*hw_reset) (struct mei_device *dev, bool enable);
 	int  (*hw_start) (struct mei_device *dev);
 	void (*hw_config) (struct mei_device *dev);
 
@@ -539,9 +539,9 @@ static inline void mei_hw_config(struct mei_device *dev)
 {
 	dev->ops->hw_config(dev);
 }
-static inline void mei_hw_reset(struct mei_device *dev, bool enable)
+static inline int mei_hw_reset(struct mei_device *dev, bool enable)
 {
-	dev->ops->hw_reset(dev, enable);
+	return dev->ops->hw_reset(dev, enable);
 }
 
 static inline void mei_hw_start(struct mei_device *dev)