[U-Boot] I2C: OMAP: spurious i2c probe addresses

Michael Jones
2011-05-25T15:38:08Z

While running v2011.06-rc1, I noticed some new behavior on my OMAP3 i2c
bus. I tracked it to commit 0e57968a215d1b, "I2C: OMAP: detect more
devices when probing an i2c bus". It detects more devices indeed, such
as some that don't even exist. Even better than that, it detects
different devices every time. It looks like just false positives, the
existent devices seem to always be found among the ghost devices.

Here's the behavior I see:
--------------------------
# i2c probe
Valid chip addresses: 05 18 30 49 50 51 5E 7A
# i2c probe
Valid chip addresses: 02 06 0B 18 1D 24 25 30 35 50 51 57 5D 6F 7C
# i2c probe
Valid chip addresses: 18 2E 30 33 35 50 51 62 6F
# i2c probe
Valid chip addresses: 18 1B 1F 2D 30 46 50 51 5C 5D
# i2c probe
Valid chip addresses: 0A 18 21 26 2B 30 32 50 51 60 66 69 6D 79
# i2c probe
Valid chip addresses: 08 09 18 1B 30 50 51 5E 6C

Here's what it looks like after reverting the commit:
------------------------------------------
# i2c probe
Valid chip addresses: 18 30 50 51
# i2c probe
Valid chip addresses: 18 30 50 51
# i2c probe
Valid chip addresses: 18 30 50 51
# i2c probe
Valid chip addresses: 18 30 50 51

-Michael