Add the hw-constraint rule
int snd_pcm_hw_rule_add(struct snd_pcm_runtime * runtime, unsigned int cond, int var, snd_pcm_hw_rule_func_t func, void * private, int dep, ...);
runtime
the pcm runtime instance
cond
condition bits
var
the variable to evaluate
func
the evaluation function
private
the private data pointer passed to function
dep
the dependent variables
...
variable arguments
Zero if successful, or a negative error code on failure.