Support for Dell XPS 15 and HDMI working on hybrid graphics?

I have a Dell XPS, the HDMI is hard wired to the discrete card. I normally want that card turned off too save battery. I use only the mini Display Port which works out of the box with an adapter to DVI/hdmi. On the rare occasions I need the graphic accelerations of the discrete card I use bumblebee. I normally totally ignore the HDMI port, as the mini DP just works and the HDMI port has issues.

I have a Dell Inspiron 7520, which is about the same age as the XPS 15 you're talking about. My Inspiron uses an ATI graphics card, which, long story short, does not work under Linux - the Radeon driver hasn't caught up with the Southern Islands card I have. The HDMI port still works, however.

However, the XPS 15 uses an Nvidia card, which works much better under Linux using Bumblebee. Bumblebee uses a neat solution to make use of the extra card, and both open-source and proprietary drivers are supported.

Also, I hear Nvidia is trying to get X to natively support hybrid graphics. Stay tuned...

I have an Dell XPS 15 L502x and the HDMI port does not work.

However this article mentions the mini DisplayPort working, so perhaps a miniDP-to-HDMI cable can solve the issue.