Hello all,
    I tried to lower the data rate if the i2c bus from 400kHz to 100kHz. I used i2c_bus=3,100 in u-boot arguments. When I reboot the system, I found the i2cbus data rate showing in boot informations was still 400kHz. In u-boot arguments, I writed 'showvar', it would show 'i2c_bus=3,100'. I'm confused.  Anyone help me.