dma: of: Remove check on always true condition (8552bb4f) · Commits · 戴 / test

Both of_dma_nbcells field of the of_dma_controller and the args_count field of the dma_spec are initialized by parsing the #dma-cells attribute of their device tree node. So if the device tree nodes of a DMA controller and the dma_spec match this means that of_dma_nbcells and args_count will also match. So the second test in the of_dma_find_controller loop is redundant because given the first test yields true the second test will also yield true. So we can safely remove the test whether of_dma_nbcells matches args_count. Since this was the last user of the of_dma_nbcells field we can remove it altogether. Signed-off-by:

Lars-Peter Clausen <lars@metafoo.de> Acked-by:

Arnd Bergmann <arnd@arndb.de> Signed-off-by:

Vinod Koul <vinod.koul@intel.com>

drivers/dma/of-dma.c

+1 −13

Original line number	Diff line number	Diff line
		@@ -35,8 +35,7 @@ static struct of_dma of_dma_find_controller(struct of_phandle_args dma_spec)
		struct of_dma *ofdma;

		list_for_each_entry(ofdma, &of_dma_list, of_dma_controllers)
		if ((ofdma->of_node == dma_spec->np) &&
		(ofdma->of_dma_nbcells == dma_spec->args_count))
		if (ofdma->of_node == dma_spec->np)
		return ofdma;

		pr_debug("%s: can't find DMA controller %s\n", __func__,
		@@ -64,7 +63,6 @@ int of_dma_controller_register(struct device_node *np,
		void *data)
		{
		struct of_dma *ofdma;
		const __be32 *prop;

		if (!np \|\| !of_dma_xlate) {
		pr_err("%s: not enough information provided\n", __func__);
		@@ -75,17 +73,7 @@ int of_dma_controller_register(struct device_node *np,
		if (!ofdma)
		return -ENOMEM;

		prop = of_get_property(np, "#dma-cells", NULL);
		if (!prop) {
		pr_err("%s: #dma-cells property is missing\n",
		__func__);
		kfree(ofdma);
		return -EINVAL;
		}


		ofdma->of_node = np;
		ofdma->of_dma_nbcells = be32_to_cpup(prop);
		ofdma->of_dma_xlate = of_dma_xlate;
		ofdma->of_dma_data = data;

include/linux/of_dma.h

+0 −1

Original line number	Diff line number	Diff line
		@@ -21,7 +21,6 @@ struct device_node;
		struct of_dma {
		struct list_head of_dma_controllers;
		struct device_node *of_node;
		int of_dma_nbcells;
		struct dma_chan (of_dma_xlate)
		(struct of_phandle_args , struct of_dma );
		void *of_dma_data;

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