ASoC: Intel: drop unnecessary list_empty (a383308e) · Commits · 戴 / test

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

+4 −6

Original line number	Diff line number	Diff line
		@@ -276,14 +276,12 @@ 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);
		}
		}
		}

		static int sst_cache_and_parse_fw(struct intel_sst_drv *sst,
		const struct firmware *fw)

sound/soc/intel/skylake/skl-pcm.c

+3 −5

Original line number	Diff line number	Diff line
		@@ -1509,12 +1509,10 @@ 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);
		}
		}

		kfree(skl->dais);

sound/soc/intel/skylake/skl-topology.c

+2 −3

Original line number	Diff line number	Diff line
		@@ -3773,7 +3773,6 @@ 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);

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