New I2C driver doesn't work in synchronous mode

[iwanttolearn]

I'm trying to use the new I2C driver (5.3.1). The problem is when I add a callback function, I can use i2c_master_transmit_receive fine, but I see a warning in the logs that says async I2C is experimental (well, this is the driver that deprecated the normal i2c.h, and it's still experimental!!!). Then I removed the callback function to go back to synchronous mode. I use the exact same i2c_master_transmit_receive call and parameters, but I get no data back! I used logic analyzer and I can see the correct data on the bus. What can be the problem?