Video players (eg. mpv) do periodic XResetScreenSaver() calls to keep the screen on while the video playing. The modesetting ddx plumbs these straight through into the kernel as DPMS setproperty ioctls, without any filtering whatsoever. When implemented via atomic these end up as empty commits on the crtc (which will nonetheless take one full frame), which leads to a dropped frame every time XResetScreenSaver() is called. Let's just filter out redundant DPMS property changes in the kernel to avoid this issue. v2: Explain the resulting commits a bit better (Sima) Document the behaviour in uapi docs (Sima) Cc: stable@vger.kernel.org Testcase: igt/kms_flip/flip-vs-dpms-on-nop Reviewed-by: Simona Vetter <simona.vetter@ffwll.ch> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20250219160239.17502-1-ville.syrjala@linux.intel.com