[PATCH] i2c: mv64xxx: Fix locked bus when offload is selected but not used on a message

[Kevin Hilman]

Jason Cooper <jason at lakedaemon.net> writes:

> On Fri, Feb 07, 2014 at 11:55:54AM +0100, Gregory CLEMENT wrote:
>> Offload can be used only on regular transactions and for 1 to byte
>> transfers. In the other cases we switch back to usual work flow.
>> 
>> In this case we need to call mv64xxx_i2c_prepare_for_io() as this
>> function is not used when we try to use offloading.
>> 
>> This commit adds this missing call when offloading have failed in the
>> MV64XXX_I2C_ACTION_OFFLOAD_SEND_START case.
>> 
>> This fix the timeout seen when the the i2c driver try to access an
>> address where the device is absent on the Armada XP bases board.
>> 
>> Cc: stable at vger.kernel.org # v3.12+
>> Fixes: 930ab3d403ae (i2c: mv64xxx: Add I2C Transaction Generator support)
>> 
>> Signed-off-by: Gregory CLEMENT <gregory.clement at free-electrons.com>
>> ---
>>  drivers/i2c/busses/i2c-mv64xxx.c | 9 ++++++++-
>>  1 file changed, 8 insertions(+), 1 deletion(-)
>
> I'd like to get a few tested-by's on this before this is pushed.  We've
> had quite a bit of fixes this round :(  Please test both multi_v7 and
> mvebu defconfigs.
>
> Kevin, I know you're busy with a lot more than us, but if you could
> confirm that this fixes the bus hangs you reported, that would be great.

I applied this patch on top of next-20140207 and tested this on the
armada-xp openblocks ax3, which is where I was seeing the I2C timeouts.

I confirm it fixes the timeouts I was seeing.

Tested-by: Kevin Hilman <khilman at linaro.org>

Kevin