[PATCH 5/7] [media] saa7134: drop unnecessary list_empty

From: Julia Lawall
Date: Sun Jul 26 2020 - 07:40:00 EST


list_for_each_safe is able to handle an empty list.
The only effect of avoiding the loop is not initializing the
index variable.
Drop list_empty tests in cases where these variables are not
used.

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

<smpl>
@@
expression x,e;
iterator name list_for_each_safe;
statement S;
identifier i,j;
@@

-if (!(list_empty(x))) {
list_for_each_safe(i,j,x) S
- }
... when != i
when != j
(
i = e;
|
? j = e;
)
</smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@xxxxxxxx>

---
drivers/media/pci/saa7134/saa7134-core.c | 14 ++++++--------
1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/drivers/media/pci/saa7134/saa7134-core.c b/drivers/media/pci/saa7134/saa7134-core.c
index e4623ed..5095f25 100644
--- a/drivers/media/pci/saa7134/saa7134-core.c
+++ b/drivers/media/pci/saa7134/saa7134-core.c
@@ -359,14 +359,12 @@ void saa7134_stop_streaming(struct saa7134_dev *dev, struct saa7134_dmaqueue *q)
struct saa7134_buf *tmp;

spin_lock_irqsave(&dev->slock, flags);
- if (!list_empty(&q->queue)) {
- list_for_each_safe(pos, n, &q->queue) {
- tmp = list_entry(pos, struct saa7134_buf, entry);
- vb2_buffer_done(&tmp->vb2.vb2_buf,
- VB2_BUF_STATE_ERROR);
- list_del(pos);
- tmp = NULL;
- }
+ list_for_each_safe(pos, n, &q->queue) {
+ tmp = list_entry(pos, struct saa7134_buf, entry);
+ vb2_buffer_done(&tmp->vb2.vb2_buf,
+ VB2_BUF_STATE_ERROR);
+ list_del(pos);
+ tmp = NULL;
}
spin_unlock_irqrestore(&dev->slock, flags);
saa7134_buffer_timeout(&q->timeout); /* also calls del_timer(&q->timeout) */