[PATCH 2/2] net: macb: kill useless use of list_empty()

From: Julia Cartwright
Date: Tue Dec 05 2017 - 15:18:41 EST


The list_for_each_entry() macro already handles the case where the list
is empty (by not executing the loop body). It's not necessary to handle
this case specially, so stop doing so.

Cc: Rafal Ozieblo <rafalo@xxxxxxxxxxx>
Signed-off-by: Julia Cartwright <julia@xxxxxx>
---
This is an additional cleanup patch found when looking at this code.

Julia

drivers/net/ethernet/cadence/macb_main.c | 34 ++++++++++++--------------------
1 file changed, 13 insertions(+), 21 deletions(-)

diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index e7ef104a077d..3643c6ad2322 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -2815,25 +2815,22 @@ static int gem_add_flow_filter(struct net_device *netdev,
spin_lock_irqsave(&bp->rx_fs_lock, flags);

/* find correct place to add in list */
- if (list_empty(&bp->rx_fs_list.list))
- list_add(&newfs->list, &bp->rx_fs_list.list);
- else {
- list_for_each_entry(item, &bp->rx_fs_list.list, list) {
- if (item->fs.location > newfs->fs.location) {
- list_add_tail(&newfs->list, &item->list);
- added = true;
- break;
- } else if (item->fs.location == fs->location) {
- netdev_err(netdev, "Rule not added: location %d not free!\n",
- fs->location);
- ret = -EBUSY;
- goto err;
- }
+ list_for_each_entry(item, &bp->rx_fs_list.list, list) {
+ if (item->fs.location > newfs->fs.location) {
+ list_add_tail(&newfs->list, &item->list);
+ added = true;
+ break;
+ } else if (item->fs.location == fs->location) {
+ netdev_err(netdev, "Rule not added: location %d not free!\n",
+ fs->location);
+ ret = -EBUSY;
+ goto err;
}
- if (!added)
- list_add_tail(&newfs->list, &bp->rx_fs_list.list);
}

+ if (!added)
+ list_add_tail(&newfs->list, &bp->rx_fs_list.list);
+
gem_prog_cmp_regs(bp, fs);
bp->rx_fs_list.count++;
/* enable filtering if NTUPLE on */
@@ -2859,11 +2856,6 @@ static int gem_del_flow_filter(struct net_device *netdev,

spin_lock_irqsave(&bp->rx_fs_lock, flags);

- if (list_empty(&bp->rx_fs_list.list)) {
- spin_unlock_irqrestore(&bp->rx_fs_lock, flags);
- return -EINVAL;
- }
-
list_for_each_entry(item, &bp->rx_fs_list.list, list) {
if (item->fs.location == cmd->fs.location) {
/* disable screener regs for the flow entry */
--
2.14.2