It has a 1080p output, like I said, my laptop gives the 1080p output on the tv

My Sony Bravia CX 520 is not giving me a 1080p output when I connect my PS3. When i select the auto settings the scrreen goes black and then comes back to the select resolution setting page. It goes till 1080i on the ps3, but when i connect my laptop it gives a 1080p output, any idea why that happens? help would be appreciated