Created attachment 113868 [details] Fixes bug by giving each monitor a different name. This makes configuring them separately impossible. One of the monitors is dual link DVI and the other one is single link DVI which pmost likely causes the issue. Fixed with attached patch.
Created attachment 113869 [details] Log from unpatched weston (Both monitors have same name: DVI1)
Created attachment 113870 [details] Log from weston patched with the above patch.
Patches should be sent to mailing list with 'git send-email'. However, the proposed patch does not use any familiar names. It seems compositor-drm.c's output naming could probably use even more fixing, looking at drmmode_create_name() in http://cgit.freedesktop.org/xorg/xserver/tree/hw/xfree86/drivers/modesetting/drmmode_display.c#n1358 . OTOH, I suppose we should leave MST support for another time, and just fix the current stuff. Comparing our name table in compositor-drm.c to that of -modesetting's, it seems it should have the same issue, Weston is missing a couple of entries, and not just DVI but also TV and HDMI entries might theoretically produce duplicates. Weston is also using slightly different names on some. Makes me wonder what convention we should follow. The actual meanings I think are authoritatively defined here with the DRM_MODE_CONNECTOR_*: http://cgit.freedesktop.org/mesa/drm/tree/include/drm/drm_mode.h#n201 The name tables just follow that exact ordering. Have you tried if Xorg with -modesetting driver has the same identical name issue? If they have, you might want to file a bug for that too.
Patch sent to the list: http://lists.freedesktop.org/archives/wayland-devel/2015-August/023971.html
The aforementioned patch has landed in trunk. https://lists.freedesktop.org/archives/wayland-devel/2015-August/024017.html
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