The legacy cursor ioctl expects to be asynchronous with respect to other screen updates, in particular page flips. As X updates the cursor from a signal context, if the cursor blocks then it will stall both the input and output chains causing bad stuttering and horrible UX. Reported-and-tested-by: Rafael Ristovski <rafael.ristovski@xxxxxxxxx> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=94980 Fixes: 5008e874edd34 ("drm/i915: Make wait_for_flips interruptible.") Suggested-by: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx> Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx> Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> Cc: Daniel Vetter <daniel.vetter@xxxxxxxx> Cc: Jani Nikula <jani.nikula@xxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx --- drivers/gpu/drm/i915/intel_display.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 4cca155376be..c5b9687091f4 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -13446,6 +13446,9 @@ static int intel_atomic_prepare_commit(struct drm_device *dev, } for_each_crtc_in_state(state, crtc, crtc_state, i) { + if (state->legacy_cursor_update) + continue; + ret = intel_crtc_wait_for_pending_flips(crtc); if (ret) return ret; -- 2.8.0.rc3 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html