We talked to the New York rapper -- who hails from the same borough A$AP is from, Harlem -- and asked for his take on the sitch in Europe, where Rocky's been in custody for nearly three weeks now on a BS assault charge ... and Dave has some interesting insights.

First off, he tell us ... yeah, A$AP shoulda been out of that jail cell a long time ago, and agrees with G-Eazy about the notion that white entertainers are simply treated differently than black ones ... which he says comes down to privilege and racism.

Dave puts it this way ... a lot of rappers that go overseas are black, rich, flashy and probably NOT what a lot of foreigners might be used to (or like, for that matter) -- and they'll wanna put an end it to it any way they can. In A$AP's case, he suggests that means lockin' him up.

Here's the kicker though -- our guy asks Dave if he's gonna join the chorus of entertainers and others who've vowed never to perform in Sweden again for the mistreatment of A$AP.