How was Joseph treated in prison?

Psalms:105:17-19:

17: He sent a man before them, even Joseph, who was sold for a servant:

18: Whose feet they hurt with fetters: he was laid in iron:

19: Until the time that his Word came: the Word of the LORD tried him.

Joseph was treated poorly at first, but eventually he earned the trust of the warden leading him to appoint Joseph in charge of the prison.

Gen:39:21: But the LORD was with Joseph, and shewed him mercy, and gave him favour in the sight of the keeper of the prison.

Gen:39:22: And the keeper of the prison committed to Joseph's hand all the prisoners that were in the prison; and whatsoever they did there, he was the doer of it.

Gen:39:23: The keeper of the prison looked not to any thing that was under his hand; because the LORD was with him, and that which he did, the LORD made it to prosper.