ASoC: fix ak4104 register array access

commit e555317c083fda01f516d2153589e82514e20e70 upstream.

Don't touch the variable 'reg' to construct the value for the actual SPI
transport. This variable is again used to access the driver's register
cache, and so random memory is overwritten.
Compute the value in-place instead.

Signed-off-by: Daniel Mack <daniel@caiaq.de>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/sound/soc/codecs/ak4104.c b/sound/soc/codecs/ak4104.c
index 3a14c6fc4f5ee45ece90bbf092bf4ba9e30cfc09..0f439ab87345588e12ec797bfea491eefc2fbc6b 100644 (file)
--- a/sound/soc/codecs/ak4104.c
+++ b/sound/soc/codecs/ak4104.c
@@ -90,12 +90,10 @@ static int ak4104_spi_write(struct snd_soc_codec *codec, unsigned int reg,
        if (reg >= codec->reg_cache_size)
                return -EINVAL;
 
-       reg &= AK4104_REG_MASK;
-       reg |= AK4104_WRITE;
-
        /* only write to the hardware if value has changed */
        if (cache[reg] != value) {
-               u8 tmp[2] = { reg, value };
+               u8 tmp[2] = { (reg & AK4104_REG_MASK) | AK4104_WRITE, value };
+
                if (spi_write(spi, tmp, sizeof(tmp))) {
                        dev_err(&spi->dev, "SPI write failed\n");
                        return -EIO;