Re: [PATCH 1/2] drm: Introduce crtc->mode_valid() callback

On Wed, May 3, 2017 at 5:21 PM, Ville Syrjälä ville.syrjala@linux.intel.com wrote:

We don't actually want the codepaths to match exactly. In i915 we allow the user to exceed some of the display/dongle limits because those things often tell us that something shouldn't work when in fact it does. And some users are quick to complain if something stops working for them.

The goal here is to share the source-side checking (crtc/encoder/bridges), and that should match perfectly between probe and commit. Sink-side constraints are different, and for those we should indeed not check everything. Maybe a good reason to only call connector->mode_valid in the probe paths? -Daniel