Regression in 16bpp between 1.18.3 and 1.18.4

Submitted by Alkis Georgopoulos

Assigned to Xorg Project Team

Link to original bug (#100295)

Description

Created attachment 130337 Xorg.0.log from 1.18.4 on kvm/cirrus with corrupted image

16bpp was working fine with the modesetting driver in xserver-xorg-core=1.18.3, but it's having various issues in 1.18.4, for example this corrupted dual image: https://launchpadlibrarian.net/311563710/VirtualBox_Thin_20_03_2017_10_32_51.png

I've tested xinit -- -depth 16 on 1.18.4 with the following combinations, all of which were working fine in 1.18.3: VirtualBox: VirtualBox Graphics Adapter [80ee:beef] | vboxvideo | modeset | vboxdrmfb ==> Corrupted small double image

kvm -vga virtio: Red Hat, Inc Device [1af4:1050] | virtio-pci | modeset | virtiodrmfb ==> Corrupted small double image

kvm -vga cirrus: Cirrus Logic GD 5446 [1013:00b8] | cirrus | modeset | cirrusdrmfb ==> Corrupted small single image. It gets fixed if I change resolution with xrandr.

I'm attaching the Xorg.0.log of that last kvm/cirrus test.

Btw, in all those cases if I put "nomodeset" in the command line I end up using the VESA driver which doesn't have the issue.

Attachment 130337, "Xorg.0.log from 1.18.4 on kvm/cirrus with corrupted image":
Xorg.0.log

Version: 7.7 (2012.06)