Subject: [2.6.37 -> 2.6.38 regression] "mv64xxx: I2C bus locked, block: 1, time_left: 0" every few seconds

From: [email-masked] (Guenter Roeck)
Date: Sat, 7 Jan 2012 16:45:02 -0800

On Sun, Jan 01, 2012 at 01:32:55AM -0600, Jonathan Nieder wrote:
> Hi,
> 
> Roman Mamedov wrote[1]:
> 
> > This bug is still present for me in the latest kernel version in
> > Debian testing (3.1.6).
> >
> > The last properly working kernel version seems to be:
> [...]
> > And the problem occurs since:
> [...]
> 
> Thanks.  Arnaud, any hints?  To summarize:
> 
>  - Michael Ott reported with Debian kernel 2.6.38-3 (which is closely
>    based on stable v2.6.38.2):
> 
> 	syslog tell me every few seconds:
> 	i2c i2c-0: mv64xxx: I2C bus locked, block: 1, time_left: 0
> 
>  - Manuel Roeder reported the same and found that upstream v2.6.38
>    triggers the problem and v2.6.37.6 does not.
> 
>  - Roman Mamedov finds the bug present in Debian 3.1.6-1 (which
>    is closely based on stable v3.1.6) and Debian 2.6.37-2 (based on
>    stable v2.6.37.2) but not Debian 2.6.37-1 (based on mainline
>    v2.6.37).
> 
> The regression range described above seems a little inconsistent to
> me, so maybe there's something more going on.
> 
Points to commit eda6bee6c7e67b5bd17bdbced0926f5687f686d5 (i2c-mv64xxx: send repeated START
between messages in xfer). Maybe you can back it out and see if it makes a difference.

Guenter