[alsa-devel] Question about snd_soc_8_8_write

[Kuninori Morimoto]

Dear Mark

I have question about snd_soc_8_8_write

-----------------------------
static int snd_soc_8_8_write(struct snd_soc_codec *codec, unsigned int reg,
			     unsigned int value)
{
	u8 *cache = codec->reg_cache;
	u8 data[2];

	BUG_ON(codec->volatile_register);

	data[0] = reg & 0xff;
	data[1] = value & 0xff;

	if (reg < codec->reg_cache_size)
		cache[reg] = value;

	if (codec->hw_write(codec->control_data, data, 2) == 2)
		return 0;
	else
		return -EIO;
}
-----------------------------

I wounder this behavior.

if reg >= codec->reg_cache_size,
this functions will call hw_write
though cache[xx] ignore it.

And 
even though if reg < codec->reg_cache_size,
if hw_write return error, cache[xx] value was still changed.

This is correct behavior ?
Or are there any reason ?

Best regards
--
Kuninori Morimoto