releases/2.6.22.14/i2c-pasemi-fix-nack-detection.patch

   1 From khali@linux-fr.org  Mon Nov 19 09:45:02 2007
   2 From: Jean Delvare <khali@linux-fr.org>
   3 Date: Fri, 16 Nov 2007 10:24:36 +0100
   4 Subject: i2c-pasemi: Fix NACK detection
   5 To: stable@kernel.org
   6 Cc: Olof Johansson <olof@lixom.net>
   7 Message-ID: <20071116102436.036f8727@hyperion.delvare>
   8
   9 From: Jean Delvare <khali@linux-fr.org>
  10
  11 patch be8a1f7cd4501c3b4b32543577a33aee6d2193ac in mainline.
  12
  13 Turns out we don't actually check the status to see if there was a
  14 device out there to talk to, just if we had a timeout when doing so.
  15
  16 Add the proper check, so we don't falsly think there are devices
  17 on the bus that are not there, etc.
  18
  19 Signed-off-by: Olof Johansson <olof@lixom.net>
  20 Signed-off-by: Jean Delvare <khali@linux-fr.org>
  21 Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
  22
  23 ---
  24  drivers/i2c/busses/i2c-pasemi.c |    5 +++++
  25  1 file changed, 5 insertions(+)
  26
  27 --- a/drivers/i2c/busses/i2c-pasemi.c
  28 +++ b/drivers/i2c/busses/i2c-pasemi.c
  29 @@ -51,6 +51,7 @@ struct pasemi_smbus {
  30  #define MRXFIFO_DATA_M 0x000000ff
  31
  32  #define SMSTA_XEN      0x08000000
  33 +#define SMSTA_MTN      0x00200000
  34
  35  #define CTL_MRR                0x00000400
  36  #define CTL_MTR                0x00000200
  37 @@ -98,6 +99,10 @@ static unsigned int pasemi_smb_waitready
  38                 status = reg_read(smbus, REG_SMSTA);
  39         }
  40
  41 +       /* Got NACK? */
  42 +       if (status & SMSTA_MTN)
  43 +               return -ENXIO;
  44 +
  45         if (timeout < 0) {
  46                 dev_warn(&smbus->dev->dev, "Timeout, status 0x%08x\n", status);
  47                 reg_write(smbus, REG_SMSTA, status);