The various list iterators are able to handle an empty list. The only effect of avoiding the loop is not initializing some index variables. Drop list_empty tests in cases where these variables are not used.
The semantic patch that makes these changes is as follows: (http://coccinelle.lip6.fr/)
<smpl> @@ expression x,e; iterator name list_for_each_entry; statement S; identifier i; @@
-if (!(list_empty(x))) { list_for_each_entry(i,x,...) S - } ... when != i ? i = e
@@ expression x,e; iterator name list_for_each_entry_safe; statement S; identifier i,j; @@
-if (!(list_empty(x))) { list_for_each_entry_safe(i,j,x,...) S - } ... when != i when != j ( i = e; | ? j = e; )
@@ expression x,e; iterator name list_for_each; statement S; identifier i; @@
-if (!(list_empty(x))) { list_for_each(i,x) S - } ... when != i ? i = e
@@ 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; )
// -------------------
@@ expression x,e; statement S; identifier i; @@
-if (!(list_empty(x))) list_for_each_entry(i,x,...) S ... when != i ? i = e
@@ expression x,e; statement S; identifier i,j; @@
-if (!(list_empty(x))) list_for_each_entry_safe(i,j,x,...) S ... when != i when != j ( i = e; | ? j = e; )
@@ expression x,e; statement S; identifier i; @@
-if (!(list_empty(x))) list_for_each(i,x) S ... when != i ? i = e
@@ expression x,e; 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>
---
drivers/media/pci/saa7134/saa7134-core.c | 14 ++--- drivers/media/usb/cx231xx/cx231xx-core.c | 16 ++---- drivers/media/usb/tm6000/tm6000-core.c | 24 +++------- drivers/net/ethernet/mellanox/mlx5/core/steering/dr_matcher.c | 13 ++--- drivers/net/ethernet/mellanox/mlx5/core/steering/dr_rule.c | 5 -- drivers/net/ethernet/sfc/ptp.c | 20 +++----- drivers/net/wireless/ath/dfs_pattern_detector.c | 15 ++---- sound/soc/intel/atom/sst/sst_loader.c | 10 +--- sound/soc/intel/skylake/skl-pcm.c | 8 +-- sound/soc/intel/skylake/skl-topology.c | 5 -- 10 files changed, 53 insertions(+), 77 deletions(-)