[Intel-gfx] Bug#926926: thinkpad_acpi: Unable to use VGA port on Lenovo Docking station after boot

[^-¨ Mário Lopes]

Package: linux-image-4.19.0-0.bpo.4-amd64
Version: 4.19.28-2~bpo9+1
X-Debbugs-CC: ibm-acpi at hmh.eng.br, ibm-acpi-devel at lists.sourceforge.net, platform-driver-x86 at vger.kernel.org, intel-gfx at lists.freedesktop.org

Dear Maintainer,

I have a Lenovo ThinkPad T480s with Intel GFX and a Lenovo ThinkPad Ultra Docking Station.
I'm using an LG monitor connected to Display Port of docking station, at 1080p at 60Hz, configured as primary monitor.
I'm also using a HannStar monitor, connected to VGA port of docking station, at 1280x1024 at 75Hz, configured as secondary monitor.
The built-in T480s screen is also active, at 2K, configured as secondary monitor.

Since updates available at 10/April, I need to reconnect the VGA cable to use the monitor after cold start. Sometimes, it's also needed to reboot the laptop.
The same also happens when I lock the computer, only when monitors enter in suspend mode and when I got into lock screen, the VGA monitor doesn't receive any signal, so VGA reconnection or system reboot is needed. The workaround for this is just to lock without sending suspending commands to monitors.

I didn't saw any relevant information on dmesg output, but I can provide relevant info from this or other place if needed.

Before 10/April, it was only needed to reconnect VGA, let's say, one per week.

Thanks.


Best regards,
Mário J. Lopes