Re: [alsa-devel] [PATCH - try2] ASoC: Codec driver for Texas Instruments tlv320dac33 codec

On Tue, 2009-10-13 at 14:03 +0200, Ujfalusi Peter (Nokia-D/Tampere) wrote:

+static int dac33_write_locked(struct snd_soc_codec *codec, unsigned int reg,

•                  unsigned int value)
  

+{

•   struct tlv320dac33_priv *dac33 = codec->private_data;
  

•   u8 data[2];
  

•   int ret = 0;
  

•   /*
  

•    * data is
  

•    *   D15..D8 dac33 register offset
  

•    *   D7...D0 register data
  

•    */
  

•   data[0] = reg & 0xff;
  

•   data[1] = value & 0xff;
  

•   dac33_write_reg_cache(codec, data[0], data[1]);
  

•   mutex_lock(&dac33->mutex);
  

•   if (dac33->chip_power) {
  

•           ret = codec->hw_write(codec->control_data, data, 2);
  

•           if (ret != 2)
  

•                   dev_err(codec->dev, "Write failed (%d)\n", ret);
  

•           else
  

•                   ret = 0;
  

•   }
  

•   mutex_unlock(&dac33->mutex);
  

•   return ret;
  

+}

Mark, aren't all codec bits updated within the snd_soc_update_bits() by DAPM? It always takes the io_mutex. Does it make sense if we proposed a new item to struct snd_soc_codec, something like io_mutex? then snd_soc_update_bits() would check the presence of this codec->io_mutex, and if it was present, it would only use that instead of io_mutex. Just an idea... (I'd help here, no need for double locking like now)