releases/2.6.36.2/asoc-remove-volatility-from-wm8900-power1-register.patch

   1 From 6d212d8e86fb4221bd91b9266b7567ee2b83bd01 Mon Sep 17 00:00:00 2001
   2 From: Mark Brown <broonie@opensource.wolfsonmicro.com>
   3 Date: Fri, 29 Oct 2010 15:41:17 -0700
   4 Subject: ASoC: Remove volatility from WM8900 POWER1 register
   5
   6 From: Mark Brown <broonie@opensource.wolfsonmicro.com>
   7
   8 commit 6d212d8e86fb4221bd91b9266b7567ee2b83bd01 upstream.
   9
  10 Not all bits can be read back from POWER1 so avoid corruption when using
  11 a read/modify/write cycle by marking it non-volatile - the only thing we
  12 read back from it is the chip revision which has diagnostic value only.
  13 We can re-add later but that's a more invasive change than is suitable
  14 for a bugfix.
  15
  16 Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
  17 Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
  18 Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
  19
  20 ---
  21  sound/soc/codecs/wm8900.c |    6 ------
  22  1 file changed, 6 deletions(-)
  23
  24 --- a/sound/soc/codecs/wm8900.c
  25 +++ b/sound/soc/codecs/wm8900.c
  26 @@ -188,7 +188,6 @@ static int wm8900_volatile_register(unsi
  27  {
  28         switch (reg) {
  29         case WM8900_REG_ID:
  30 -       case WM8900_REG_POWER1:
  31                 return 1;
  32         default:
  33                 return 0;
  34 @@ -1236,11 +1235,6 @@ static __devinit int wm8900_i2c_probe(st
  35                 goto err;
  36         }
  37
  38 -       /* Read back from the chip */
  39 -       reg = snd_soc_read(codec, WM8900_REG_POWER1);
  40 -       reg = (reg >> 12) & 0xf;
  41 -       dev_info(&i2c->dev, "WM8900 revision %d\n", reg);
  42 -
  43         wm8900_reset(codec);
  44
  45         /* Turn the chip on */