Only specific N value (0x8000) would be acceptable for LG LP140WF6-SPM1 eDP panel which is running at asynchronous clock mode. With the other N value, it will enter BITS mode and display black screen. This patch series set constant N value for specific sink/branch device that would cover similar issue. Cc: Jani Nikula <jani.nikula@xxxxxxxxx> Cc: Cooper Chiou <cooper.chiou@xxxxxxxxx> Cc: Matt Atwood <matthew.s.atwood@xxxxxxxxx> Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx> Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@xxxxxxxxx> Cc: Clint Taylor <clinton.a.taylor@xxxxxxxxx> Lee, Shawn C (3): drm: Add support for device_id based detection. drm: Change limited M/N quirk to constant N quirk. drm: add LG eDP panel to quirk database drivers/gpu/drm/drm_dp_helper.c | 17 ++++++++++++++++- drivers/gpu/drm/i915/intel_display.c | 28 +++++++++++++--------------- drivers/gpu/drm/i915/intel_display.h | 2 +- drivers/gpu/drm/i915/intel_dp.c | 8 ++++---- drivers/gpu/drm/i915/intel_dp_mst.c | 6 +++--- include/drm/drm_dp_helper.h | 6 +++--- 6 files changed, 40 insertions(+), 27 deletions(-) -- 2.7.4 _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel