Andrea Dworkin was an influential feminist mainly in the '80 and '90. She was pretty clearly anti pornography, at least as it existed in her time (she died in 2005. Who knows what she might think of some of the stuff out there today). She’s also one of the most frequently misquoted feminists of all time, particularly by anti-feminists. she did not say all heterosexual intercourse was rape:

Several reviewers accused you of saying that all intercourse was rape. I haven’t found a hint of that anywhere in the book. Is that what you are saying?

Andrea Dworkin: No, I wasn’t saying that and I didn’t say that, then or ever. There is a long section in Right-Wing Women on intercourse in marriage. My point was that as long as the law allows statutory exemption for a husband from rape charges, no married woman has legal protection from rape. I also argued, based on a reading of our laws, that marriage mandated intercourse—it was compulsory, part of the marriage contract. Under the circumstances, I said, it was impossible to view sexual intercourse in marriage as the free act of a free woman. I said that when we look at sexual liberation and the law, we need to look not only at which sexual acts are forbidden, but which are compelled.

The whole issue of intercourse as this culture’s penultimate expression of male dominance became more and more interesting to me. In Intercourse I decided to approach the subject as a social practice, material reality. This may be my history, but I think the social explanation of the “all sex is rape” slander is different and probably simple. Most men and a good number of women experience sexual pleasure in inequality. Since the paradigm for sex has been one of conquest, possession, and violation, I think many men believe they need an unfair advantage, which at its extreme would be called rape. I don’t think they need it. I think both intercourse and sexual pleasure can and will survive equality.

It’s important to say, too, that the pornographers, especially Playboy, have published the “all sex is rape” slander repeatedly over the years, and it’s been taken up by others like Time who, when challenged, cannot cite a source in my work.