staging/mei: don't check if list is empty before looping

1. No need to check if a list is empty before list_for_each_ looping as
this is already checked by loop stopping conditional.

The side effect is reduced indentation depth
from:
	if (!list_empty)
		list_for_each()
to:
	list_for_each()

2. drop cb_ prefix from cl_pos, cl_next variables used in list_for_each
loops. The code is more compact and readable
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/mei/init.c

@@ -48,20 +48,15 @@ void mei_io_list_init(struct mei_io_list *list)
  */
 void mei_io_list_flush(struct mei_io_list *list, struct mei_cl *cl)
 {
-	struct mei_cl_cb *cb_pos = NULL;
-	struct mei_cl_cb *cb_next = NULL;
-
-
-	if (list_empty(&list->mei_cb.cb_list))
-		return;
+	struct mei_cl_cb *pos = NULL;
+	struct mei_cl_cb *next = NULL;
 
-	list_for_each_entry_safe(cb_pos, cb_next,
-				 &list->mei_cb.cb_list, cb_list) {
-		if (cb_pos) {
+	list_for_each_entry_safe(pos, next, &list->mei_cb.cb_list, cb_list) {
+		if (pos) {
 			struct mei_cl *cl_tmp;
-			cl_tmp = (struct mei_cl *)cb_pos->file_private;
+			cl_tmp = (struct mei_cl *)pos->file_private;
 			if (mei_cl_cmp_id(cl, cl_tmp))
-				list_del(&cb_pos->cb_list);
+				list_del(&pos->cb_list);
 		}
 	}
 }
@@ -335,7 +330,6 @@ void mei_reset(struct mei_device *dev, int interrupts_enabled)
 		}
 	}
 	/* remove all waiting requests */
-	if (!list_empty(&dev->write_list.mei_cb.cb_list)) {
 	list_for_each_entry_safe(cb_pos, cb_next,
 			&dev->write_list.mei_cb.cb_list, cb_list) {
 		if (cb_pos) {
@@ -344,7 +338,6 @@ void mei_reset(struct mei_device *dev, int interrupts_enabled)
 			cb_pos = NULL;
 		}
 	}
-	}
 }
 
 

drivers/staging/mei/interrupt.c

@@ -412,9 +412,9 @@ static void mei_client_connect_response(struct mei_device *dev,
 		dev->iamthif_state = MEI_IAMTHIF_IDLE;
 		return;
 	}
-	if (!list_empty(&dev->ctrl_rd_list.mei_cb.cb_list)) {
 	list_for_each_entry_safe(cb_pos, cb_next,
 				&dev->ctrl_rd_list.mei_cb.cb_list, cb_list) {
+
 		cl = (struct mei_cl *)cb_pos->file_private;
 		if (!cl) {
 			list_del(&cb_pos->cb_list);
@@ -429,7 +429,6 @@ static void mei_client_connect_response(struct mei_device *dev,
 			}
 		}
 	}
-	}
 }
 
 /**
@@ -453,7 +452,6 @@ static void mei_client_disconnect_response(struct mei_device *dev,
 			rs->host_addr,
 			rs->status);
 
-	if (!list_empty(&dev->ctrl_rd_list.mei_cb.cb_list)) {
 	list_for_each_entry_safe(cb_pos, cb_next,
 			&dev->ctrl_rd_list.mei_cb.cb_list, cb_list) {
 		cl = (struct mei_cl *)cb_pos->file_private;
@@ -476,7 +474,6 @@ static void mei_client_disconnect_response(struct mei_device *dev,
 			break;
 		}
 	}
-	}
 }
 
 /**
@@ -1222,7 +1219,7 @@ static int mei_irq_thread_write_handler(struct mei_io_list *cmpl_list,
 {
 
 	struct mei_cl *cl;
-	struct mei_cl_cb *cb_pos = NULL, *cb_next = NULL;
+	struct mei_cl_cb *pos = NULL, *next = NULL;
 	struct mei_io_list *list;
 	int ret;
 
@@ -1235,29 +1232,27 @@ static int mei_irq_thread_write_handler(struct mei_io_list *cmpl_list,
 	dev_dbg(&dev->pdev->dev, "complete all waiting for write cb.\n");
 
 	list = &dev->write_waiting_list;
-	if (!list_empty(&list->mei_cb.cb_list)) {
-		list_for_each_entry_safe(cb_pos, cb_next,
+	list_for_each_entry_safe(pos, next,
 			&list->mei_cb.cb_list, cb_list) {
-			cl = (struct mei_cl *)cb_pos->file_private;
-			if (cl) {
+		cl = (struct mei_cl *)pos->file_private;
+		if (cl == NULL)
+			continue;
+
 		cl->status = 0;
-				list_del(&cb_pos->cb_list);
+		list_del(&pos->cb_list);
 		if (MEI_WRITING == cl->writing_state &&
-				   (cb_pos->major_file_operations ==
-						MEI_WRITE) &&
+		   (pos->major_file_operations == MEI_WRITE) &&
 		   (cl != &dev->iamthif_cl)) {
 			dev_dbg(&dev->pdev->dev,
 				"MEI WRITE COMPLETE\n");
-					cl->writing_state =
-							MEI_WRITE_COMPLETE;
-					list_add_tail(&cb_pos->cb_list,
+			cl->writing_state = MEI_WRITE_COMPLETE;
+			list_add_tail(&pos->cb_list,
 				&cmpl_list->mei_cb.cb_list);
 		}
 		if (cl == &dev->iamthif_cl) {
 			dev_dbg(&dev->pdev->dev, "check iamthif flow control.\n");
 			if (dev->iamthif_flow_control_pending) {
-						ret =
-						_mei_irq_thread_iamthif_read(
+				ret = _mei_irq_thread_iamthif_read(
 						dev, slots);
 				if (ret)
 					return ret;
@@ -1265,9 +1260,6 @@ static int mei_irq_thread_write_handler(struct mei_io_list *cmpl_list,
 		}
 	}
 
-		}
-	}
-
 	if (dev->stop && !dev->wd_pending) {
 		dev->wd_stopped = true;
 		wake_up_interruptible(&dev->wait_stop_wd);
@@ -1312,24 +1304,24 @@ static int mei_irq_thread_write_handler(struct mei_io_list *cmpl_list,
 
 	/* complete control write list CB */
 	dev_dbg(&dev->pdev->dev, "complete control write list cb.\n");
-	list_for_each_entry_safe(cb_pos, cb_next,
+	list_for_each_entry_safe(pos, next,
 				&dev->ctrl_wr_list.mei_cb.cb_list, cb_list) {
-		cl = (struct mei_cl *) cb_pos->file_private;
+		cl = (struct mei_cl *) pos->file_private;
 		if (!cl) {
-			list_del(&cb_pos->cb_list);
+			list_del(&pos->cb_list);
 			return -ENODEV;
 		}
-		switch (cb_pos->major_file_operations) {
+		switch (pos->major_file_operations) {
 		case MEI_CLOSE:
 			/* send disconnect message */
-			ret = _mei_irq_thread_close(dev, slots, cb_pos, cl, cmpl_list);
+			ret = _mei_irq_thread_close(dev, slots, pos, cl, cmpl_list);
 			if (ret)
 				return ret;
 
 			break;
 		case MEI_READ:
 			/* send flow control message */
-			ret = _mei_irq_thread_read(dev, slots, cb_pos, cl, cmpl_list);
+			ret = _mei_irq_thread_read(dev, slots, pos, cl, cmpl_list);
 			if (ret)
 				return ret;
 
@@ -1338,7 +1330,7 @@ static int mei_irq_thread_write_handler(struct mei_io_list *cmpl_list,
 			/* connect message */
 			if (!mei_other_client_is_connecting(dev, cl))
 				continue;
-			ret = _mei_irq_thread_ioctl(dev, slots, cb_pos, cl, cmpl_list);
+			ret = _mei_irq_thread_ioctl(dev, slots, pos, cl, cmpl_list);
 			if (ret)
 				return ret;
 
@@ -1350,16 +1342,15 @@ static int mei_irq_thread_write_handler(struct mei_io_list *cmpl_list,
 
 	}
 	/* complete  write list CB */
-	if (!list_empty(&dev->write_list.mei_cb.cb_list)) {
 	dev_dbg(&dev->pdev->dev, "complete write list cb.\n");
-		list_for_each_entry_safe(cb_pos, cb_next,
+	list_for_each_entry_safe(pos, next,
 			&dev->write_list.mei_cb.cb_list, cb_list) {
-			cl = (struct mei_cl *)cb_pos->file_private;
+		cl = (struct mei_cl *)pos->file_private;
+		if (cl == NULL)
+			continue;
 
-			if (cl) {
 		if (cl != &dev->iamthif_cl) {
-					if (!mei_flow_ctrl_creds(dev,
-						cl)) {
+			if (!mei_flow_ctrl_creds(dev, cl)) {
 				dev_dbg(&dev->pdev->dev,
 					"No flow control"
 				    " credentials for client"
@@ -1368,7 +1359,7 @@ static int mei_irq_thread_write_handler(struct mei_io_list *cmpl_list,
 				continue;
 			}
 			ret = _mei_irq_thread_cmpl(dev, slots,
-							    cb_pos,
+					    pos,
 					    cl, cmpl_list);
 			if (ret)
 				return ret;
@@ -1376,8 +1367,7 @@ static int mei_irq_thread_write_handler(struct mei_io_list *cmpl_list,
 		} else if (cl == &dev->iamthif_cl) {
 			/* IAMTHIF IOCTL */
 			dev_dbg(&dev->pdev->dev, "complete amthi write cb.\n");
-					if (!mei_flow_ctrl_creds(dev,
-							cl)) {
+			if (!mei_flow_ctrl_creds(dev, cl)) {
 				dev_dbg(&dev->pdev->dev,
 					"No flow control"
 				    " credentials for amthi"
@@ -1387,17 +1377,15 @@ static int mei_irq_thread_write_handler(struct mei_io_list *cmpl_list,
 			}
 			ret = _mei_irq_thread_cmpl_iamthif(dev,
 						slots,
-								cb_pos,
+						pos,
 						cl,
 						cmpl_list);
 			if (ret)
 				return ret;
 
 		}
-			}
 
 	}
-	}
 	return 0;
 }
 
@@ -1487,11 +1475,7 @@ void mei_timer(struct work_struct *work)
 			amthi_complete_list = &dev->amthi_read_complete_list.
 					mei_cb.cb_list;
 
-			if (!list_empty(amthi_complete_list)) {
-
-				list_for_each_entry_safe(cb_pos, cb_next,
-							amthi_complete_list,
-							cb_list) {
+			list_for_each_entry_safe(cb_pos, cb_next, amthi_complete_list, cb_list) {
 
 				cl_pos = cb_pos->file_object->private_data;
 
@@ -1499,7 +1483,6 @@ void mei_timer(struct work_struct *work)
 				if (cl_pos == &dev->iamthif_cl)
 					list_del(&cb_pos->cb_list);
 			}
-			}
 			if (dev->iamthif_current_cb)
 				mei_free_cb_private(dev->iamthif_current_cb);
 

drivers/staging/mei/iorw.c

@@ -228,17 +228,15 @@ struct mei_cl_cb *find_amthi_read_list_entry(
 		struct file *file)
 {
 	struct mei_cl *cl_temp;
-	struct mei_cl_cb *cb_pos = NULL;
-	struct mei_cl_cb *cb_next = NULL;
+	struct mei_cl_cb *pos = NULL;
+	struct mei_cl_cb *next = NULL;
 
-	if (!list_empty(&dev->amthi_read_complete_list.mei_cb.cb_list)) {
-		list_for_each_entry_safe(cb_pos, cb_next,
+	list_for_each_entry_safe(pos, next,
 	    &dev->amthi_read_complete_list.mei_cb.cb_list, cb_list) {
-			cl_temp = (struct mei_cl *)cb_pos->file_private;
+		cl_temp = (struct mei_cl *)pos->file_private;
 		if (cl_temp && cl_temp == &dev->iamthif_cl &&
-				cb_pos->file_object == file)
-				return cb_pos;
-		}
+			pos->file_object == file)
+			return pos;
 	}
 	return NULL;
 }
@@ -549,8 +547,8 @@ int amthi_write(struct mei_device *dev, struct mei_cl_cb *cb)
 void mei_run_next_iamthif_cmd(struct mei_device *dev)
 {
 	struct mei_cl *cl_tmp;
-	struct mei_cl_cb *cb_pos = NULL;
-	struct mei_cl_cb *cb_next = NULL;
+	struct mei_cl_cb *pos = NULL;
+	struct mei_cl_cb *next = NULL;
 	int status;
 
 	if (!dev)
@@ -564,16 +562,15 @@ void mei_run_next_iamthif_cmd(struct mei_device *dev)
 	dev->iamthif_timer = 0;
 	dev->iamthif_file_object = NULL;
 
-	if (!list_empty(&dev->amthi_cmd_list.mei_cb.cb_list)) {
 	dev_dbg(&dev->pdev->dev, "complete amthi cmd_list cb.\n");
 
-		list_for_each_entry_safe(cb_pos, cb_next,
+	list_for_each_entry_safe(pos, next,
 			&dev->amthi_cmd_list.mei_cb.cb_list, cb_list) {
-			list_del(&cb_pos->cb_list);
-			cl_tmp = (struct mei_cl *)cb_pos->file_private;
+		list_del(&pos->cb_list);
+		cl_tmp = (struct mei_cl *)pos->file_private;
 
 		if (cl_tmp && cl_tmp == &dev->iamthif_cl) {
-				status = amthi_write(dev, cb_pos);
+			status = amthi_write(dev, pos);
 			if (status) {
 				dev_dbg(&dev->pdev->dev,
 					"amthi write failed status = %d\n",
@@ -583,7 +580,6 @@ void mei_run_next_iamthif_cmd(struct mei_device *dev)
 			break;
 		}
 	}
-	}
 }
 
 /**

drivers/staging/mei/main.c

@@ -198,20 +198,17 @@ static struct mei_cl_cb *find_read_list_entry(
 		struct mei_device *dev,
 		struct mei_cl *cl)
 {
-	struct mei_cl_cb *cb_pos = NULL;
-	struct mei_cl_cb *cb_next = NULL;
-
-	if (!list_empty(&dev->read_list.mei_cb.cb_list)) {
+	struct mei_cl_cb *pos = NULL;
+	struct mei_cl_cb *next = NULL;
 
 	dev_dbg(&dev->pdev->dev, "remove read_list CB\n");
-		list_for_each_entry_safe(cb_pos, cb_next,
+	list_for_each_entry_safe(pos, next,
 			&dev->read_list.mei_cb.cb_list, cb_list) {
 		struct mei_cl *cl_temp;
-			cl_temp = (struct mei_cl *)cb_pos->file_private;
+		cl_temp = (struct mei_cl *)pos->file_private;
 
 		if (mei_cl_cmp_id(cl, cl_temp))
-				return cb_pos;
-		}
+			return pos;
 	}
 	return NULL;
 }