skl_update_other_pipe_wm+0x210/0x220 [i915_bpo]() on mouse move to other screen

When I move the mouse from screen to screen, I get this in my dmesg/syslog:

May 22 15:31:25 melk kernel: [15834.052811] WARNING: CPU: 1 PID: 1534 at /build/linux-lts-vivid-naHA4g/linux-lts-vivid-3.19.0/ubuntu/i915/intel_pm.c:3406 skl_update_other_pipe_wm+0x210/0x220 [i915_bpo]()
May 22 15:31:25 melk kernel: [15834.052812] WARN_ON(!wm_changed)

Linux Mint 17.3 KDE. Details:

System: Host: melk Kernel: 3.19.0-32-generic x86_64 (64 bit) Desktop: N/A Distro: Linux Mint 17.3 Rosa
Machine: Mobo: MSI model: H170A PC MATE (MS-7971) v: 2.0 Bios: American Megatrends v: B.50 date: 01/25/2016
CPU: Quad core Intel Core i5-6500 (-MCP-) cache: 6144 KB
           clock speeds: max: 3201 MHz 1: 3201 MHz 2: 800 MHz 3: 800 MHz 4: 800 MHz
Graphics: Card: Intel Sky Lake Integrated Graphics
           Display Server: X.org 1.17.1 drivers: intel (unloaded: fbdev,vesa)
           tty size: 271x72 Advanced Data: N/A for root
Audio: Card-1 C-Media CMI8788 [Oxygen HD Audio] driver: snd_virtuoso Sound: ALSA v: k3.19.0-32-generic
           Card-2 Logitech Webcam C270 driver: USB Audio
Network: Card: Realtek RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller driver: r8169
           IF: eth0 state: up speed: 1000 Mbps duplex: full mac: <filter>
Drives: HDD Total Size: NA (-) ID-1: /dev/sda model: WDC_WD15EARS size: 1500.3GB
           ID-2: /dev/sdb model: WDC_WD15EARS size: 1500.3GB
Partition: ID-1: / size: 23G used: 5.9G (27%) fs: ext4 dev: /dev/nvme0n1p1
           ID-2: /home size: 212G used: 81G (40%) fs: ext4 dev: /dev/nvme0n1p2
RAID: Device-1: /dev/md1 - active raid: 1 components: online: 2/2 - sda3 sdb3
           Device-2: /dev/md0 - active raid: 1 components: online: 2/2 - sda2 sdb2
           Device-3: /dev/md2 - active raid: 1 components: online: 2/2 - sda4 sdb4
Sensors: System Temperatures: cpu: 29.8C mobo: 27.8C
           Fan Speeds (in rpm): cpu: N/A
Info: Processes: 226 Uptime: 4:28 Memory: 1971.5/15939.6MB Client: Shell (bash) inxi: 2.2.28