i2c i2c-2: I2C write to 0x2d failed, err -27 on Xserve G5

Hi all,
I'm running this kernel:
[  +0.000000] Linux version 3.16.0-4-powerpc64
(debian-kernel@lists.debian.org) (gcc version 4.8.4 (Debian
4.8.4-1) ) #1 SMP Debian 3.16.7-ckt11-1+deb8u3 (2015-08-04)

on my Xserve G5, and it works great except these messages keep
coming in dmesg:
[Sep 4 19:11] i2c i2c-2: I2C write to 0x2d failed, err -27
[Sep 4 19:29] i2c i2c-2: I2C write to 0x2d failed, err -27
[Sep 4 20:04] i2c i2c-2: I2C write to 0x2d failed, err -27
[Sep 4 20:29] i2c i2c-2: I2C write to 0x2d failed, err -27

Is this a known problem, or has been fixed in a newer version
since this branch in Debian? I see in the mailing list, there are
some i2c related fixes. I can run a kernel.org kernel + apply
patches if that should help. See attached full dmesg and lspci 
for more details. Thanks!  
-Nick