ASoC: Do not write to invalid registers on the wm9712.
Eric Millbrandt [Tue, 22 Dec 2009 15:13:24 +0000 (10:13 -0500)]
This patch fixes a bug where "virtual" registers were being written to the ac97
bus.  This was causing unrelated registers to become corrupted (headphone 0x04,
touchscreen 0x78, etc).

This patch duplicates protection that was included in the wm9713 driver.

Signed-off-by: Eric Millbrandt <emillbrandt@dekaresearch.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: stable@kernel.org

sound/soc/codecs/wm9712.c

index 0ac1215..e237bf6 100644 (file)
@@ -463,7 +463,8 @@ static int ac97_write(struct snd_soc_codec *codec, unsigned int reg,
 {
        u16 *cache = codec->reg_cache;
 
-       soc_ac97_ops.write(codec->ac97, reg, val);
+       if (reg < 0x7c)
+               soc_ac97_ops.write(codec->ac97, reg, val);
        reg = reg >> 1;
        if (reg < (ARRAY_SIZE(wm9712_reg)))
                cache[reg] = val;