mei: fix mei_poll operation

mei_poll returned with POLLIN w/o checking whether the operation
has really completed.
remove redundant check and locking in amthif specific handler
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/mei/amthif.c

@@ -362,6 +362,18 @@ int mei_amthif_write(struct mei_cl *cl, struct mei_cl_cb *cb)
 	return mei_amthif_run_next_cmd(dev);
 }
 
+/**
+ * mei_amthif_poll - the amthif poll function
+ *
+ * @dev: the device structure
+ * @file: pointer to file structure
+ * @wait: pointer to poll_table structure
+ *
+ * Return: poll mask
+ *
+ * Locking: called under "dev->device_lock" lock
+ */
+
 unsigned int mei_amthif_poll(struct mei_device *dev,
 		struct file *file, poll_table *wait)
 {
@@ -369,19 +381,12 @@ unsigned int mei_amthif_poll(struct mei_device *dev,
 
 	poll_wait(file, &dev->iamthif_cl.wait, wait);
 
-	mutex_lock(&dev->device_lock);
-	if (!mei_cl_is_connected(&dev->iamthif_cl)) {
-
-		mask = POLLERR;
-
-	} else if (dev->iamthif_state == MEI_IAMTHIF_READ_COMPLETE &&
+	if (dev->iamthif_state == MEI_IAMTHIF_READ_COMPLETE &&
 	    dev->iamthif_file_object == file) {
 
-		mask |= (POLLIN | POLLRDNORM);
-		dev_dbg(dev->dev, "run next amthif cb\n");
+		mask |= POLLIN | POLLRDNORM;
 		mei_amthif_run_next_cmd(dev);
 	}
-	mutex_unlock(&dev->device_lock);
 
 	return mask;
 }

drivers/misc/mei/client.c

@@ -1299,7 +1299,7 @@ void mei_cl_complete(struct mei_cl *cl, struct mei_cl_cb *cb)
 	} else if (cb->fop_type == MEI_FOP_READ) {
 		list_add_tail(&cb->list, &cl->rd_completed);
 		if (waitqueue_active(&cl->rx_wait))
-			wake_up_interruptible(&cl->rx_wait);
+			wake_up_interruptible_all(&cl->rx_wait);
 		else
 			mei_cl_bus_rx_event(cl);
 

drivers/misc/mei/main.c

@@ -542,6 +542,7 @@ static long mei_compat_ioctl(struct file *file,
  */
 static unsigned int mei_poll(struct file *file, poll_table *wait)
 {
+	unsigned long req_events = poll_requested_events(wait);
 	struct mei_cl *cl = file->private_data;
 	struct mei_device *dev;
 	unsigned int mask = 0;
@@ -558,22 +559,19 @@ static unsigned int mei_poll(struct file *file, poll_table *wait)
 		goto out;
 	}
 
-	mutex_unlock(&dev->device_lock);
-
-
-	if (cl == &dev->iamthif_cl)
-		return mei_amthif_poll(dev, file, wait);
-
-	poll_wait(file, &cl->tx_wait, wait);
-
-	mutex_lock(&dev->device_lock);
-
-	if (!mei_cl_is_connected(cl)) {
-		mask = POLLERR;
+	if (cl == &dev->iamthif_cl) {
+		mask = mei_amthif_poll(dev, file, wait);
 		goto out;
 	}
 
-	mask |= (POLLIN | POLLRDNORM);
+	if (req_events & (POLLIN | POLLRDNORM)) {
+		poll_wait(file, &cl->rx_wait, wait);
+
+		if (!list_empty(&cl->rd_completed))
+			mask |= POLLIN | POLLRDNORM;
+		else
+			mei_cl_read_start(cl, 0, file);
+	}
 
 out:
 	mutex_unlock(&dev->device_lock);