Created attachment 213131 [details] dmesg I was trying to find a way for my Haswell system (Thinkpad T440p, 20AN0034RT, i5-4300M) to enter deeper power-saving package states (below pc3) and it turned out, that after following actions system indeed goes to pc7: 1. Setting i915.enable_psr=1 2. Setting SATA link_power_management_policy to min_power But immediately after that the problem occurs. External VGA monitor is no longer usable, as it starts flickering constantly every second: it is switching between two states: whole area is black, except the small horizontal line on top and it's normal condition. Main screen screen is flickering too, but not so hard and is effectively usable. Main screen becomes black only for fraction of second and rarely. As in 4.6 PSR became enabled by default I decided to report this.
Please file new drm/i915 bugs at the freedesktop.org bugzilla: https://bugs.freedesktop.org/enter_bug.cgi?product=DRI&component=DRM/Intel