Comment 24 for bug 1771185

I can also confirm the problem. The Ubuntu 18.04LTS (updated everything) does NOT sense when I disconnect the HDMI. There is no change in /sys. This uis the mainb problem, I guess. The events does not generate screen switching.

Very annoying when the screen locked and disconnected from external monitor, the notebook display remaions black!

I checked the status, and it STILL shown connected but the HDMI monitor was disconnected:

----
root@notebook:~# cat /sys/class/drm/card0-HDMI-A-1/status
connected
root@notebook:~# cat /sys/class/drm/card0-HDMI-A-1/status
connected
root@notebook:~# cat /sys/class/drm/card0-HDMI-A-1/status

----

HW: Dell Lattitude 7490
----

Sometimes work, sometimes NOT.

It is very annoying when I work with the notebook, it's screen remains black after I disconnect the external monitor. I created Keyboard shortucts to force screen UP:

Lspci:
00:00.0 Host bridge: Intel Corporation Xeon E3-1200 v6/7th Gen Core Processor Host Bridge/DRAM Registers (rev 02)
00:02.0 VGA compatible controller: Intel Corporation HD Graphics 620 (rev 02)
00:04.0 Signal processing controller: Intel Corporation Xeon E3-1200 v5/E3-1500 v5/6th Gen Core Processor Thermal Subsystem (rev 02)
00:14.0 USB controller: Intel Corporation Sunrise Point-LP USB 3.0 xHCI Controller (rev 21)
00:14.2 Signal processing controller: Intel Corporation Sunrise Point-LP Thermal subsystem (rev 21)
00:15.0 Signal processing controller: Intel Corporation Sunrise Point-LP Serial IO I2C Controller #0 (rev 21)
00:15.1 Signal processing controller: Intel Corporation Sunrise Point-LP Serial IO I2C Controller #1 (rev 21)
00:15.2 Signal processing controller: Intel Corporation Sunrise Point-LP Serial IO I2C Controller #2 (rev 21)
00:15.3 Signal processing controller: Intel Corporation Sunrise Point-LP Serial IO I2C Controller #3 (rev 21)
00:16.0 Communication controller: Intel Corporation Sunrise Point-LP CSME HECI #1 (rev 21)
00:16.3 Serial controller: Intel Corporation Device 9d3d (rev 21)
00:17.0 SATA controller: Intel Corporation Sunrise Point-LP SATA Controller [AHCI mode] (rev 21)
00:1c.0 PCI bridge: Intel Corporation Sunrise Point-LP PCI Express Root Port #1 (rev f1)
00:1c.2 PCI bridge: Intel Corporation Sunrise Point-LP PCI Express Root Port #3 (rev f1)
00:1f.0 ISA bridge: Intel Corporation Intel(R) 100 Series Chipset Family LPC Controller/eSPI Controller - 9D4E (rev 21)
00:1f.2 Memory controller: Intel Corporation Sunrise Point-LP PMC (rev 21)
00:1f.3 Audio device: Intel Corporation Sunrise Point-LP HD Audio (rev 21)
00:1f.4 SMBus: Intel Corporation Sunrise Point-LP SMBus (rev 21)
00:1f.6 Ethernet controller: Intel Corporation Ethernet Connection (4) I219-LM (rev 21)
01:00.0 Unassigned class [ff00]: Realtek Semiconductor Co., Ltd. RTS525A PCI Express Card Reader (rev 01)
02:00.0 Network controller: Intel Corporation Wireless 8265 / 8275 (rev 78)

------
root@notebook:~# uname -a
Linux notebook 4.18.0-16-generic #17~18.04.1-Ubuntu SMP Tue Feb 12 13:35:51 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux
------