I am going to page @Rick19744 for good reason.
Partnerships have two bases: an inside basis and an outside basis.
There is no doubt whatsoever that your outside basis is stepped up to its fair market value on the date of death.
However, there may be a disparity between the inside and outside basis after the step-up and that can only be cured by the partnership - I think (a section of the Code allows for this (I believe it's 743) but the election has to be made by the partnership under Section 754 - @Rick19744 can confirm or deny this).
