Hello Kuninori Morimoto,

The patch cc64c390b215: "ASoC: rsnd: adg: clearly handle clock error / NULL case" from Aug 20, 2021, leads to the following Smatch static checker warning:

sound/soc/sh/rcar/adg.c:396 rsnd_adg_create_null_clk() warn: passing zero to 'ERR_CAST'

sound/soc/sh/rcar/adg.c 386 static struct clk *rsnd_adg_create_null_clk(struct rsnd_priv *priv, 387 const char * const name, 388 const char *parent) 389 { 390 struct device *dev = rsnd_priv_to_dev(priv); 391 struct clk *clk; 392 393 clk = clk_register_fixed_rate(dev, name, parent, 0, 0); 394 if (IS_ERR_OR_NULL(clk)) { 395 dev_err(dev, "create null clk error\n");

The clk_register_fixed_rate() function doesn't have any documentation, but generally when functions return a mix of error pointers and NULL then the NULL case means the feature is deliberately disabled. So it should not print an error message. Perhaps an info message at most.

--> 396 return ERR_CAST(clk);

No need to cast this. The types are the same.

397 } 398 399 return clk; 400 }

regards, dan carpenter