Hebrews 2:10, what is the meaning of perfecting Jesus through sufferings?

Hebrews 2:10 (ASV):

For it became him, for whom are all things, and through whom are all things, in bringing many sons unto glory, to make the author of their salvation perfect through sufferings.

What is the meaning of perfecting Jesus through sufferings?

Isn’t He already perfect?

Aren’t sufferings of the Christ for Salvation of the Sinners, not for perfection of the Christ?