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ASoC: Remove volatility from WM8900 POWER1 register
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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>
Cc: stable@kernel.org
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Mark Brown committed Nov 1, 2010
1 parent c593b52 commit 6d212d8
Showing 1 changed file with 0 additions and 6 deletions.
6 changes: 0 additions & 6 deletions sound/soc/codecs/wm8900.c
Original file line number Diff line number Diff line change
Expand Up @@ -186,7 +186,6 @@ static int wm8900_volatile_register(unsigned int reg)
{
switch (reg) {
case WM8900_REG_ID:
case WM8900_REG_POWER1:
return 1;
default:
return 0;
Expand Down Expand Up @@ -1200,11 +1199,6 @@ static int wm8900_probe(struct snd_soc_codec *codec)
return -ENODEV;
}

/* Read back from the chip */
reg = snd_soc_read(codec, WM8900_REG_POWER1);
reg = (reg >> 12) & 0xf;
dev_info(codec->dev, "WM8900 revision %d\n", reg);

wm8900_reset(codec);

/* Turn the chip on */
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