Tennessee residents only file a tax return if their interest and dividend income exceeded $1,250 ($2,500 for joint filers). This is the Hall income tax.
If you're a resident in one of the remaining "taxable" states and you earned money working in one of these "tax-free" states, that income needs to be reported on your resident state return.
For example, if you're a California resident and worked in tax-free Texas, you'd still have to report your Texas earnings on your California return as well as your federal return.
Similarly, if you're a resident of tax-free Texas and earned money in California, you'd still have to file a nonresident California return to report your earnings, and you'd report those on your federal return as well.