Since commit 
38cbf9598feba97de9f9b43efa9153fd7c1a2ec9
("ASoC: core: Try to use regmap if the driver doesn't set up any I/O")
any ASoC codec which doesn't set codec::control_data is assumed
to use regmap.  That doesn't work with AC97 so this workaround
sets the codec::control_data member to a random value to restore
proper behaviour.
Tested with WM9712.
Signed-off-by: Manuel Lauss <manuel.lauss@googlemail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
 
        printk(KERN_INFO "AD1980 SoC Audio Codec\n");
 
+       codec->control_data = codec;    /* we don't use regmap! */
        ret = snd_soc_new_ac97_codec(codec, &soc_ac97_ops, 0);
        if (ret < 0) {
                printk(KERN_ERR "ad1980: failed to register AC97 codec\n");
 
 
        printk(KERN_INFO "STAC9766 SoC Audio Codec %s\n", STAC9766_VERSION);
 
+       codec->control_data = codec;    /* we don't use regmap! */
        ret = snd_soc_new_ac97_codec(codec, &soc_ac97_ops, 0);
        if (ret < 0)
                goto codec_err;
 
 {
        int ret = 0;
 
+       codec->control_data = codec;    /* we don't use regmap! */
        ret = snd_soc_new_ac97_codec(codec, &soc_ac97_ops, 0);
        if (ret < 0) {
                printk(KERN_ERR "wm9712: failed to register AC97 codec\n");
 
        if (wm9713 == NULL)
                return -ENOMEM;
        snd_soc_codec_set_drvdata(codec, wm9713);
+       codec->control_data = wm9713;   /* we don't use regmap! */
 
        ret = snd_soc_new_ac97_codec(codec, &soc_ac97_ops, 0);
        if (ret < 0)