ASoC: Remove volatility from WM8900 POWER1 register

commit 6d212d8e86fb4221bd91b9266b7567ee2b83bd01 upstream.

Not all bits can be read back from POWER1 so avoid corruption when using
a read/modify/write cycle by marking it non-volatile - the only thing we
read back from it is the chip revision which has diagnostic value only.
We can re-add later but that's a more invasive change than is suitable
for a bugfix.

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

diff --git a/sound/soc/codecs/wm8900.c b/sound/soc/codecs/wm8900.c
index 5da17a704e5a9ba2d40d27a14b24a0fff701594e..4b8ffc2ea71ddbdeb01913a40f26efb7a071c107 100644 (file)
--- a/sound/soc/codecs/wm8900.c
+++ b/sound/soc/codecs/wm8900.c
@@ -188,7 +188,6 @@ static int wm8900_volatile_register(unsigned int reg)
 {
        switch (reg) {
        case WM8900_REG_ID:
-       case WM8900_REG_POWER1:
                return 1;
        default:
                return 0;
@@ -1236,11 +1235,6 @@ static __devinit int wm8900_i2c_probe(struct i2c_client *i2c,
                goto err;
        }
 
-       /* Read back from the chip */
-       reg = snd_soc_read(codec, WM8900_REG_POWER1);
-       reg = (reg >> 12) & 0xf;
-       dev_info(&i2c->dev, "WM8900 revision %d\n", reg);
-
        wm8900_reset(codec);
 
        /* Turn the chip on */