Not only do the pageflip work without it at non-native modes (i.e. with the panel fitter enabled), it also causes normal (non-pageflipped) modesets to fail. Reported-by: Adam Jackson <ajax at redhat.com> Cc: Adam Jackson <ajax at redhat.com> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk> --- drivers/gpu/drm/i915/intel_display.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index b2c29a5..2319838 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -7902,7 +7902,13 @@ static int intel_gen6_queue_flip(struct drm_device *dev, OUT_RING(fb->pitches[0] | obj->tiling_mode); OUT_RING(obj->gtt_offset); - pf = I915_READ(PF_CTL(intel_crtc->pipe)) & PF_ENABLE; + /* Contrary to the suggestions in the documentation, + * "Enable Panel Fitter" does not seem to be required when page + * flipping with a non-native mode, and worse causes a normal + * modeset to fail. + * pf = I915_READ(PF_CTL(intel_crtc->pipe)) & PF_ENABLE; + */ + pf = 0; pipesrc = I915_READ(PIPESRC(intel_crtc->pipe)) & 0x0fff0fff; OUT_RING(pf | pipesrc); ADVANCE_LP_RING(); -- 1.7.10