Working with librtlsdr
rtlsdr_demod_write_reg failed with -7
For now, it looks like this error will come up if you are trying to run your rtl-sdr from within a VM. USB timeouts values need to be a little more relaxed.
Solution: Increase the value of CONTROL_TIMEOUT in librtlsdr.c
Sample rate incorrect in sync mode
Problem: If you set your block read size too small, sync mode reads will cap out around 200 ksps (at least on my VM).
Solution: Need to use a bigger block read size in order to meet your desired read size (16384 seems to be adequate for my purposes).