[PATCH] [107/223] ASoC: Remove volatility from WM8900 POWER1 register

From: Andi Kleen
Date: Sun Dec 12 2010 - 19:11:45 EST


2.6.35-longterm review patch. If anyone has any objections, please let me know.

------------------
From: Mark Brown <broonie@xxxxxxxxxxxxxxxxxxxxxxxxxxx>

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@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
Acked-by: Liam Girdwood <lrg@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>

---
sound/soc/codecs/wm8900.c | 6 ------
1 file changed, 6 deletions(-)

Index: linux/sound/soc/codecs/wm8900.c
===================================================================
--- linux.orig/sound/soc/codecs/wm8900.c
+++ linux/sound/soc/codecs/wm8900.c
@@ -188,7 +188,6 @@ static int wm8900_volatile_register(unsi
{
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(st
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 */
--
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