https://bugs.freedesktop.org/show_bug.cgi?id=91871
Jani Nikula jani.nikula@intel.com changed:
What |Removed |Added ---------------------------------------------------------------------------- CC| |conselvan2@gmail.com, | |intel-gfx-bugs@lists.freede | |sktop.org Component|General |DRM/Intel Assignee|dri-devel@lists.freedesktop |intel-gfx-bugs@lists.freede |.org |sktop.org QA Contact| |intel-gfx-bugs@lists.freede | |sktop.org
--- Comment #1 from Jani Nikula jani.nikula@intel.com --- To be fair, the same limitation was there before atomic.
Part of the problem is our modeset sequence, which we can't easily backtrack if the modeset fails at link training phase. Another part is that even if our modeset sequence supported that, we couldn't just reduce the mode to accommodate the lower link rate behind userspace's back. (We already pick the lowest rate that can support the mode; there's no margin to reduce.) We'd have to involve userspace somehow.
Drivers are free to use the drm dp helpers or use their own hooks for modeset. I think we should look at this from drm/i915 perspective, at least at first, so resassigning to DRM/Intel. If we come up with a way to negotiate this with userspace, that should be a generic solution.