Re: [alsa-devel] [PATCH V2] ASoC: tlv320aic3x: Fix codec pll configure bug

On Tue, Jun 26, 2012 at 11:33:43AM +0530, Hebbar, Gururaja wrote:

In sound/soc/codecs/tlv320aic3x.c

    data = snd_soc_read(codec, AIC3X_PLL_PROGA_REG);
    snd_soc_write(codec, AIC3X_PLL_PROGA_REG,
                  data | (pll_p << PLLP_SHIFT));

In the above code, pll-p value is OR'ed with previous value without clearing it. Bug is not seen if pll-p value doesn't change across Sampling frequency.

A better fix is to change the code to use snd_soc_update_bits() rather than open code it. This is more idiomatic and will suppress writes if they don't change anything.