The devm usage initially guided by iio was incorrect as pointed out by Dmitry.
reverted the change. Go forward. Go backward. But like Koen pointed out once. Any feedback is good feedback. MIA is the worst. So i should remain thankful :)
And on another note,
fifo storage was 32 bit. But actual adc data was 16 bit.
iio didn't like it. Changed it. memory usage is a bit optimized now.
And the hope/wait begins