In The Mouth of Madness 
John Carpenter explicitly does HP Lovecraft in this film about an author who sends his readers into psychotic frenzy.
"Do you read Sutter Cane?" Boom axe through the window! An excellent late entry into the JC cannon, keeps you hooked right from the beginning and keeps you right there until the crazy, bug eyed, manic laughing end!
Unbelievably I'd never seen this one and I am a self proclaimed Carpenter addict so to fix that I found that the US blu is region free and ordered myself one for something like £8.00 from amazon. I'm glad that I did because this is now one of my favourites!
You've all seen it, but I highly recommend it anyways!