[1.] One line summary of the problem: Switching to multiple monitors in VMWare only shows a black screen
[2.] Full description of the problem/report: After updating to the 5.7.* kernel, whenever I try switching to multiple monitors, the screen turns to black, and stays that way until I switch to a single monitor again. By downgrading the kernel, I have pinpointed this issue to the 5.7 kernel release. The 5.6.15 kernel doesn't have this issue, and every version of the kernel from 5.7 has it.
In the attached dmesg output, the command buffer error that happens at 20.856529 happens exactly when switching to multiple monitors for the first time. Subsequent monitor switching doesn't output any more error messages.
[3.] Keywords (i.e., modules, networking, kernel): kernel, graphics, drivers
[4.] Kernel information [4.1.] Kernel version (from /proc/version): Linux version 5.7.3-arch1-1 (linux@archlinux) (gcc version 10.1.0 (GCC), GNU ld (GNU Binutils) 2.34.0) #1 SMP PREEMPT Wed, 17 Jun 2020 19:42:12 +0000
[4.2.] Kernel .config file: Attached
[5.] Most recent kernel version which did not have the bug: 5.6.15
[8.] Environment [8.1.] Software (add the output of the ver_linux script here) Arch Linux, KDE 5.19.1-1 Attached ver_linux
[8.2.] Processor information (from /proc/cpuinfo): Attached
[8.3.] Module information (from /proc/modules): Attached
[8.4.] Loaded driver and hardware information (/proc/ioports, /proc/iomem) Attached
[8.5.] PCI information ('lspci -vvv' as root) Attached
[8.6.] SCSI information (from /proc/scsi/scsi) Attached
[8.7.] Other information that might be relevant to the problem (please look in /proc and include all information that you think to be relevant): dmesg output attached.