4.8-stable review patch. If anyone has any objections, please let me know.
------------------ From: David Wu <david...@rock-chips.com> commit 399c168ab5ab5e12ed55b6c91d61c24eb84c9164 upstream. We found a bug that i2c transfer sometimes failed on 3066a board with stabel-4.8, the con register would be updated by uninitialized tuning value, it made the i2c transfer failed. So give the tuning value to be zero during rk3x_i2c_v0_calc_timings. Signed-off-by: David Wu <david...@rock-chips.com> Tested-by: Andy Yan <andy....@rock-chips.com> Reviewed-by: Douglas Anderson <diand...@chromium.org> Signed-off-by: Wolfram Sang <w...@the-dreams.de> Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org> --- drivers/i2c/busses/i2c-rk3x.c | 2 ++ 1 file changed, 2 insertions(+) --- a/drivers/i2c/busses/i2c-rk3x.c +++ b/drivers/i2c/busses/i2c-rk3x.c @@ -694,6 +694,8 @@ static int rk3x_i2c_v0_calc_timings(unsi t_calc->div_low--; t_calc->div_high--; + /* Give the tuning value 0, that would not update con register */ + t_calc->tuning = 0; /* Maximum divider supported by hw is 0xffff */ if (t_calc->div_low > 0xffff) { t_calc->div_low = 0xffff;