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ASoC: Intel: drop unnecessary list_empty
authorJulia Lawall <Julia.Lawall@inria.fr>
Sun, 26 Jul 2020 10:58:26 +0000 (12:58 +0200)
committerMark Brown <broonie@kernel.org>
Thu, 30 Jul 2020 21:38:39 +0000 (22:38 +0100)
list_for_each_entry_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.

Note that list_for_each_entry_safe is defined in terms of
list_first_entry, which indicates that it should not be used on an
empty list.  But in list_for_each_entry_safe, the element obtained by
list_first_entry is not really accessed, only the address of its
list_head field is compared to the address of the list head, so the
list_first_entry is safe.

The semantic patch that makes this change is as follows (with another
variant for the no brace case): (http://coccinelle.lip6.fr/)

<smpl>
@@
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;
)
</smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Link: https://lore.kernel.org/r/1595761112-11003-2-git-send-email-Julia.Lawall@inria.fr
Signed-off-by: Mark Brown <broonie@kernel.org>
sound/soc/intel/atom/sst/sst_loader.c
sound/soc/intel/skylake/skl-pcm.c
sound/soc/intel/skylake/skl-topology.c

index 8ad0ca7..fc91a30 100644 (file)
@@ -276,12 +276,10 @@ void sst_memcpy_free_resources(struct intel_sst_drv *sst_drv_ctx)
        struct sst_memcpy_list *listnode, *tmplistnode;
 
        /* Free the list */
-       if (!list_empty(&sst_drv_ctx->memcpy_list)) {
-               list_for_each_entry_safe(listnode, tmplistnode,
-                               &sst_drv_ctx->memcpy_list, memcpylist) {
-                       list_del(&listnode->memcpylist);
-                       kfree(listnode);
-               }
+       list_for_each_entry_safe(listnode, tmplistnode,
+                                &sst_drv_ctx->memcpy_list, memcpylist) {
+               list_del(&listnode->memcpylist);
+               kfree(listnode);
        }
 }
 
index 268ba16..5dee55e 100644 (file)
@@ -1509,11 +1509,9 @@ int skl_platform_unregister(struct device *dev)
        struct skl_dev *skl = bus_to_skl(bus);
        struct skl_module_deferred_bind *modules, *tmp;
 
-       if (!list_empty(&skl->bind_list)) {
-               list_for_each_entry_safe(modules, tmp, &skl->bind_list, node) {
-                       list_del(&modules->node);
-                       kfree(modules);
-               }
+       list_for_each_entry_safe(modules, tmp, &skl->bind_list, node) {
+               list_del(&modules->node);
+               kfree(modules);
        }
 
        kfree(skl->dais);
index b9aab47..b7d2d97 100644 (file)
@@ -3773,9 +3773,8 @@ void skl_tplg_exit(struct snd_soc_component *component, struct hdac_bus *bus)
        struct skl_dev *skl = bus_to_skl(bus);
        struct skl_pipeline *ppl, *tmp;
 
-       if (!list_empty(&skl->ppl_list))
-               list_for_each_entry_safe(ppl, tmp, &skl->ppl_list, node)
-                       list_del(&ppl->node);
+       list_for_each_entry_safe(ppl, tmp, &skl->ppl_list, node)
+               list_del(&ppl->node);
 
        /* clean up topology */
        snd_soc_tplg_component_remove(component, SND_SOC_TPLG_INDEX_ALL);