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>

4 files changed, 152 insertions, 183 deletions

diff --git a/drivers/staging/mei/init.c b/drivers/staging/mei/init.c
index 4cc184e..32cf05e 100644
--- a/drivers/staging/mei/init.c
+++ b/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);
 		}
 	}
 }
@@ -335,14 +330,12 @@ 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) {
-				list_del(&cb_pos->cb_list);
-				mei_free_cb_private(cb_pos);
-				cb_pos = NULL;
-			}
+	list_for_each_entry_safe(cb_pos, cb_next,
+			&dev->write_list.mei_cb.cb_list, cb_list) {
+		if (cb_pos) {
+			list_del(&cb_pos->cb_list);
+			mei_free_cb_private(cb_pos);
+			cb_pos = NULL;
 		}
 	}
 }
diff --git a/drivers/staging/mei/interrupt.c b/drivers/staging/mei/interrupt.c
index ab9c4c0..38e0197 100644
--- a/drivers/staging/mei/interrupt.c
+++ b/drivers/staging/mei/interrupt.c
@@ -412,21 +412,20 @@ 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_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);
+			return;
+		}
+		if (MEI_IOCTL == cb_pos->major_file_operations) {
+			if (is_treat_specially_client(cl, rs)) {
 				list_del(&cb_pos->cb_list);
-				return;
-			}
-			if (MEI_IOCTL == cb_pos->major_file_operations) {
-				if (is_treat_specially_client(cl, rs)) {
-					list_del(&cb_pos->cb_list);
-					cl->status = 0;
-					cl->timer_count = 0;
-					break;
-				}
+				cl->status = 0;
+				cl->timer_count = 0;
+				break;
 			}
 		}
 	}
@@ -453,28 +452,26 @@ 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;
+	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);
-				return;
-			}
+		if (!cl) {
+			list_del(&cb_pos->cb_list);
+			return;
+		}
 
-			dev_dbg(&dev->pdev->dev, "list_for_each_entry_safe in ctrl_rd_list.\n");
-			if (cl->host_client_id == rs->host_addr &&
-			    cl->me_client_id == rs->me_addr) {
+		dev_dbg(&dev->pdev->dev, "list_for_each_entry_safe in ctrl_rd_list.\n");
+		if (cl->host_client_id == rs->host_addr &&
+		    cl->me_client_id == rs->me_addr) {
 
-				list_del(&cb_pos->cb_list);
-				if (!rs->status)
-					cl->state = MEI_FILE_DISCONNECTED;
+			list_del(&cb_pos->cb_list);
+			if (!rs->status)
+				cl->state = MEI_FILE_DISCONNECTED;
 
-				cl->status = 0;
-				cl->timer_count = 0;
-				break;
-			}
+			cl->status = 0;
+			cl->timer_count = 0;
+			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;
 
@@ -1235,36 +1232,31 @@ 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->mei_cb.cb_list, cb_list) {
-			cl = (struct mei_cl *)cb_pos->file_private;
-			if (cl) {
-				cl->status = 0;
-				list_del(&cb_pos->cb_list);
-				if (MEI_WRITING == cl->writing_state &&
-				   (cb_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,
-						&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(
-								dev, slots);
-						if (ret)
-							return ret;
-					}
-				}
+	list_for_each_entry_safe(pos, next,
+			&list->mei_cb.cb_list, cb_list) {
+		cl = (struct mei_cl *)pos->file_private;
+		if (cl == NULL)
+			continue;
+
+		cl->status = 0;
+		list_del(&pos->cb_list);
+		if (MEI_WRITING == cl->writing_state &&
+		   (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(&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(
+						dev, slots);
+				if (ret)
+					return ret;
 			}
-
 		}
 	}
 
@@ -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;
 
@@ -1350,53 +1342,49 @@ 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,
-				&dev->write_list.mei_cb.cb_list, cb_list) {
-			cl = (struct mei_cl *)cb_pos->file_private;
-
-			if (cl) {
-				if (cl != &dev->iamthif_cl) {
-					if (!mei_flow_ctrl_creds(dev,
-						cl)) {
-						dev_dbg(&dev->pdev->dev,
-							"No flow control"
-						    " credentials for client"
-						    " %d, not sending.\n",
-						    cl->host_client_id);
-						continue;
-					}
-					ret = _mei_irq_thread_cmpl(dev, slots,
-							    cb_pos,
-							    cl, cmpl_list);
-					if (ret)
-						return ret;
-
-				} 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)) {
-						dev_dbg(&dev->pdev->dev,
-							"No flow control"
-						    " credentials for amthi"
-						    " client %d.\n",
-						    cl->host_client_id);
-						continue;
-					}
-					ret = _mei_irq_thread_cmpl_iamthif(dev,
-								slots,
-								cb_pos,
-								cl,
-								cmpl_list);
-					if (ret)
-						return ret;
+	dev_dbg(&dev->pdev->dev, "complete write list cb.\n");
+	list_for_each_entry_safe(pos, next,
+			&dev->write_list.mei_cb.cb_list, cb_list) {
+		cl = (struct mei_cl *)pos->file_private;
+		if (cl == NULL)
+			continue;
+
+		if (cl != &dev->iamthif_cl) {
+			if (!mei_flow_ctrl_creds(dev, cl)) {
+				dev_dbg(&dev->pdev->dev,
+					"No flow control"
+				    " credentials for client"
+				    " %d, not sending.\n",
+				    cl->host_client_id);
+				continue;
+			}
+			ret = _mei_irq_thread_cmpl(dev, slots,
+					    pos,
+					    cl, cmpl_list);
+			if (ret)
+				return ret;
 
-				}
+		} 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)) {
+				dev_dbg(&dev->pdev->dev,
+					"No flow control"
+				    " credentials for amthi"
+				    " client %d.\n",
+				    cl->host_client_id);
+				continue;
 			}
+			ret = _mei_irq_thread_cmpl_iamthif(dev,
+						slots,
+						pos,
+						cl,
+						cmpl_list);
+			if (ret)
+				return ret;
 
 		}
+
 	}
 	return 0;
 }
@@ -1487,18 +1475,13 @@ 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;
 
-					cl_pos = cb_pos->file_object->private_data;
-
-					/* Finding the AMTHI entry. */
-					if (cl_pos ==	&dev->iamthif_cl)
-						list_del(&cb_pos->cb_list);
-				}
+				/* Finding the AMTHI entry. */
+				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);
diff --git a/drivers/staging/mei/iorw.c b/drivers/staging/mei/iorw.c
index 36d0465..841092b 100644
--- a/drivers/staging/mei/iorw.c
+++ b/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;
-
-	if (!list_empty(&dev->amthi_read_complete_list.mei_cb.cb_list)) {
-		list_for_each_entry_safe(cb_pos, cb_next,
-		    &dev->amthi_read_complete_list.mei_cb.cb_list, cb_list) {
-			cl_temp = (struct mei_cl *)cb_pos->file_private;
-			if (cl_temp && cl_temp == &dev->iamthif_cl &&
-				cb_pos->file_object == file)
-				return cb_pos;
-		}
+	struct mei_cl_cb *pos = NULL;
+	struct mei_cl_cb *next = NULL;
+
+	list_for_each_entry_safe(pos, next,
+	    &dev->amthi_read_complete_list.mei_cb.cb_list, cb_list) {
+		cl_temp = (struct mei_cl *)pos->file_private;
+		if (cl_temp && cl_temp == &dev->iamthif_cl &&
+			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)
@@ -564,24 +562,22 @@ 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,
-		    &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;
-
-			if (cl_tmp && cl_tmp == &dev->iamthif_cl) {
-				status = amthi_write(dev, cb_pos);
-				if (status) {
-					dev_dbg(&dev->pdev->dev,
-						"amthi write failed status = %d\n",
-							status);
-					return;
-				}
-				break;
+	dev_dbg(&dev->pdev->dev, "complete amthi cmd_list cb.\n");
+
+	list_for_each_entry_safe(pos, next,
+			&dev->amthi_cmd_list.mei_cb.cb_list, cb_list) {
+		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, pos);
+			if (status) {
+				dev_dbg(&dev->pdev->dev,
+					"amthi write failed status = %d\n",
+						status);
+				return;
 			}
+			break;
 		}
 	}
 }
diff --git a/drivers/staging/mei/main.c b/drivers/staging/mei/main.c
index b470bb0..cb216af 100644
--- a/drivers/staging/mei/main.c
+++ b/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;
+	struct mei_cl_cb *pos = NULL;
+	struct mei_cl_cb *next = NULL;
 
-	if (!list_empty(&dev->read_list.mei_cb.cb_list)) {
+	dev_dbg(&dev->pdev->dev, "remove read_list CB\n");
+	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 *)pos->file_private;
 
-		dev_dbg(&dev->pdev->dev, "remove read_list CB\n");
-		list_for_each_entry_safe(cb_pos, cb_next,
-				&dev->read_list.mei_cb.cb_list, cb_list) {
-			struct mei_cl *cl_temp;
-			cl_temp = (struct mei_cl *)cb_pos->file_private;
-
-			if (mei_cl_cmp_id(cl, cl_temp))
-				return cb_pos;
-		}
+		if (mei_cl_cmp_id(cl, cl_temp))
+			return pos;
 	}
 	return NULL;
 }