Questions[displayport](ubuntu)

I have decided to try switching to Ubuntu in a dual-boot scenario with Windows 10, and things work perfectly overall, but I have encountered one bug that really ruins the experience. I get my sound from my monitor from the displayport cable that is connected to the GPU, and this works without any issues on Windows, but on Ubuntu I've had two separate issues with it.

The first is that the system would just randomly switch from DisplayPort 3 as a audio output source to Digital Output, something that I fixed through Pavucontrol.

But the other issue, which is just as annoying, is the sound delay. Whenever I resume a video after a minute or two, the video starts, but the audio only starts after a few seconds of silence, making the entire experience be very jarring. I've set the latency in Pavucontrol to 0 but this doesn't fix it. Using Alsamixer to mute all but one of the S/PDIF options seems to help somewhat, but not completely.

I've tried to look around the internet for help, but that only made me even more confused than before, with bug reports of sound delays on HDMI from 2015 and someone suggesting a complicated measure that would have essentially played silent sounds at all times.

Is there anything I can do?

I am having problems setting up a right resolution after changing HDMI->DisplayPort adapter (converter).

My setup:

• laptop HP Folio 9470m running Ubuntu 18.04.4 LTS (system is up to date, no pending updates)
• Samsung 27" CH711 Curved High Resolution QLED

As this monitor has a HDMI cable and the laptop has only Display port, I am using a DisplayPort to HDMI adapter. Everything worked until recently (I was able to set 2560x1440 resolution without any problem). Cable is probably old and it started to disconnect and connect quite often (turning the screen off for few seconds). I decided to get a new adapter so I got ICY BOX (up to 4K resolution, they say).

It is already the second one I am trying but I am not able to select higher resolution with it than 1920x1080:

But I am able to do that with an old cable which is constantly reconnecting:

I have no idea what brand is the old adapter but it looks pretty normal:

Does anyone have an idea what might be the problem?

EDIT

With old adapter (has 2560x1440 but old and needs to be replaced):

matt:~ $ xrandr --listmonitors
Monitors: 1
 0: +*DP-3 2560/597x1440/336+0+0  DP-3
matt:~ $ xrandr -q
Screen 0: minimum 320 x 200, current 2560 x 1440, maximum 8192 x 8192
LVDS-1 connected (normal left inverted right x axis y axis)
   1600x900      60.04 +  59.99    59.94    59.95    59.82    40.02  
   1440x900      59.89  
   1400x900      59.96    59.88  
   1440x810      60.00    59.97  
   1368x768      59.88    59.85  
   1360x768      59.80    59.96  
   1280x800      59.99    59.97    59.81    59.91  
   1152x864      60.00  
   1280x720      60.00    59.99    59.86    59.74  
   1024x768      60.04    60.00  
   960x720       60.00  
   928x696       60.05  
   896x672       60.01  
   1024x576      59.95    59.96    59.90    59.82  
   960x600       59.93    60.00  
   960x540       59.96    59.99    59.63    59.82  
   800x600       60.00    60.32    56.25  
   840x525       60.01    59.88  
   864x486       59.92    59.57  
   800x512       60.17  
   700x525       59.98  
   800x450       59.95    59.82  
   640x512       60.02  
   720x450       59.89  
   700x450       59.96    59.88  
   640x480       60.00    59.94  
   720x405       59.51    58.99  
   684x384       59.88    59.85  
   680x384       59.80    59.96  
   640x400       59.88    59.98  
   576x432       60.06  
   640x360       59.86    59.83    59.84    59.32  
   512x384       60.00  
   512x288       60.00    59.92  
   480x270       59.63    59.82  
   400x300       60.32    56.34  
   432x243       59.92    59.57  
   320x240       60.05  
   360x202       59.51    59.13  
   320x180       59.84    59.32  
VGA-1 disconnected (normal left inverted right x axis y axis)
HDMI-1 disconnected (normal left inverted right x axis y axis)
DP-1 disconnected (normal left inverted right x axis y axis)
HDMI-2 disconnected (normal left inverted right x axis y axis)
HDMI-3 disconnected (normal left inverted right x axis y axis)
DP-2 disconnected (normal left inverted right x axis y axis)
DP-3 connected primary 2560x1440+0+0 (normal left inverted right x axis y axis) 597mm x 336mm
   2560x1440     59.95*+
   1920x1080     60.00    50.00    59.94  
   1680x1050     59.88  
   1600x900      60.00  
   1280x1024     75.02    60.02  
   1440x900      59.90  
   1280x800      59.91  
   1152x864      75.00  
   1280x720      60.00    50.00    59.94  
   1024x768      75.03    70.07    60.00  
   832x624       74.55  
   800x600       72.19    75.00    60.32    56.25  
   720x576       50.00  
   720x480       60.00    59.94  
   640x480       75.00    72.81    66.67    60.00    59.94  
   720x400       70.08  
  2560x1440_60.00 (0x18b) 312.250MHz -HSync +VSync
        h: width  2560 start 2752 end 3024 total 3488 skew    0 clock  89.52KHz
        v: height 1440 start 1443 end 1448 total 1493           clock  59.96Hz

With new adapter (the one without 2560x1440 resolution):

matt:~ $ xrandr --listmonitors
Monitors: 1
 0: +*HDMI-3 1920/597x1080/336+0+0  HDMI-3
matt:~ $ xrandr -q
Screen 0: minimum 320 x 200, current 1920 x 1080, maximum 8192 x 8192
LVDS-1 connected (normal left inverted right x axis y axis)
   1600x900      60.04 +  59.99    59.94    59.95    59.82    40.02  
   1440x900      59.89  
   1400x900      59.96    59.88  
   1440x810      60.00    59.97  
   1368x768      59.88    59.85  
   1360x768      59.80    59.96  
   1280x800      59.99    59.97    59.81    59.91  
   1152x864      60.00  
   1280x720      60.00    59.99    59.86    59.74  
   1024x768      60.04    60.00  
   960x720       60.00  
   928x696       60.05  
   896x672       60.01  
   1024x576      59.95    59.96    59.90    59.82  
   960x600       59.93    60.00  
   960x540       59.96    59.99    59.63    59.82  
   800x600       60.00    60.32    56.25  
   840x525       60.01    59.88  
   864x486       59.92    59.57  
   800x512       60.17  
   700x525       59.98  
   800x450       59.95    59.82  
   640x512       60.02  
   720x450       59.89  
   700x450       59.96    59.88  
   640x480       60.00    59.94  
   720x405       59.51    58.99  
   684x384       59.88    59.85  
   680x384       59.80    59.96  
   640x400       59.88    59.98  
   576x432       60.06  
   640x360       59.86    59.83    59.84    59.32  
   512x384       60.00  
   512x288       60.00    59.92  
   480x270       59.63    59.82  
   400x300       60.32    56.34  
   432x243       59.92    59.57  
   320x240       60.05  
   360x202       59.51    59.13  
   320x180       59.84    59.32  
VGA-1 disconnected (normal left inverted right x axis y axis)
HDMI-1 disconnected (normal left inverted right x axis y axis)
DP-1 disconnected (normal left inverted right x axis y axis)
HDMI-2 disconnected (normal left inverted right x axis y axis)
HDMI-3 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 597mm x 336mm
   1920x1080     60.00*   50.00    59.94  
   1680x1050     59.88  
   1600x900      60.00  
   1280x1024     75.02    60.02  
   1440x900      59.90  
   1280x800      59.91  
   1152x864      75.00  
   1280x720      60.00    50.00    59.94  
   1024x768      75.03    70.07    60.00  
   832x624       74.55  
   800x600       72.19    75.00    60.32    56.25  
   720x576       50.00  
   720x480       60.00    59.94  
   640x480       75.00    72.81    66.67    60.00    59.94  
   720x400       70.08  
DP-2 disconnected (normal left inverted right x axis y axis)
DP-3 disconnected (normal left inverted right x axis y axis)
  2560x1440_60.00 (0x18b) 312.250MHz -HSync +VSync
        h: width  2560 start 2752 end 3024 total 3488 skew    0 clock  89.52KHz
        v: height 1440 start 1443 end 1448 total 1493           clock  59.96Hz

Hardware: lenovo thinkpad e480 laptop (intel+amd hybrid graphics) + lenovo thinkpad usb-c dock + dell u2415 monitor. Bios / dock firmware: latest versions installed

If external monitor is connected to displayport or vga on dock (no HDMI / dvi ports there), I get running bright pixels on monitor, and sometimes monitor just randomly turns off and on (sometimes few times per minute, sometimes few times per hour). Tested on Ubuntu 18.04 / 19.04, got the same result

On Windows 10 I still get running pixels (but almost invisible) when refresh rates are 59/60 for laptop/external displays, and everything works perfectly when refresh rates are 60/60 - so it looks like hardware is OK

On Ubuntu (both 18.04 and 19.04) everything works fine when external monitor is connected to HDMI port on laptop (no displayport there) - so it looks like intel graphics drivers are OK

Tried to:

• install appropriate displaylink drivers for 18.04 (nothing changes)
• install appropriate displaylink drivers for 19.04 (nothing changes)
• install amdgpu drivers (failed, uninstall failed too)
• change laptop refresh rate (didn't help, but pixels are "running" differently for different rate)
• set refresh rates 60/60 (didn't work, those are not possible values)
• set kernel parameter i915.edp_vswing=2 (didn't help)
• set i915.preliminary_hw_support=1 (didn't help)
• set intel_idle.max_cstate (to different values, didn't help)
• use vga_switcheroo to switch to amd graphics card (failed, commands didn't change anything, even in su mode)

How can I fix this issue with dock displayports / vga?

I have been using a Dell xps 15 9560 laptop with Ubuntu 16.04 since the 9560 was released. In December of 2018, I received two Dell U2717D monitors and have been connecting them to my laptop so that I could have three displays (my laptop's screen plus the two monitors). I have been using a USB-C to Displayport connection for one monitor and just straight HDMI for the other. This has been working well for me up until this morning (nearly three months after receiving the monitors).

This morning, as usual, I opened my laptop, plugged in both monitors, and switched them on. Everything was seemingly normal except my computer's background was not appearing on any of my displays, though I could go on the internet and open all other applications just fine (though things were a bit glitchy). I attributed this to standard Linux-related headaches, so I decided to restart my computer. Now here is where things get interesting. My computer booted up as normal and everything was displaying on all three monitors during bootup but, once I logged in, both external monitors said that they were not receiving signal from my laptop. I decided I should unplug both and plug them back in, as you do, to see if that would change anything. Once I unplugged the HDMI cable, my second monitor popped up its normal display. I plugged the HDMI cable back in, both monitors displayed the same "no ____ signal from your device" again. I then unplugged the USB-C connection and the HDMI-connected monitor popped its normal display back up. I plugged the USB-C cable back in and, yet again, I was met with "no ____ signal from your device" on both monitors yet again.

At this point I was mildly frustrated and I looked in the display settings and it showed only one external monitor plugged in (keep in mind they are both plugged in at this time) and it was set to "off" so I toggled it to "on" and nothing happened. Using xrandr, it shows that both monitors are connected. Now here is where things get even stranger. I decided to just restart my computer once more and, during the restart process, both monitors immediately displayed their normal contents. Even on boot, both external monitors were displaying their normal contents. I finally made it to the login screen, typed in my password and pressed enter (feeling accomplished at this point for doing nothing). Immediately upon signing in, both external monitors immediately gave me their "no ____ signal from your device" messages once again. Now I am here and wondering if anyone knows what could possibly be the cause of this. I did quite a bit of searching online but it seems that no one has run into this specific problem.

A side note, I do not know if it matters, but I was able to connect my phone to my computer via USB-C with the HDMI monitor also connected and everything worked just fine. I am literally only running into problems when I am signed in.

TL;DR

Laptop: Dell xps 15 9560

OS: Ubuntu 16.04

Problem: Have two external monitors (both Dell U2717D), one connected via HDMI and the other connected via USB-C to Displayport. Setup worked for three months, then, randomly, stopped working this morning when both are plugged in. Both work fine during shutdown and boot sequence but, once I login, I can only get one to work at a time.

Thank you in advance for any insights/assistance.

Edit: For what it is worth, I am using kernel 4.8.0-41-generic

Everything worked fine until yesterday :) I use a mini-DP to connect to my screen for over a year now. Now, when I connect the cable it recognizes it (so I see the Ubuntu background in the screen and can work in my laptop) but when I close the lid or set the monitor as the main screen (so as to work only from the monitor screen as I have been doing), the whole system freezes. Removing the cable does nothing. Only hard reboot (pressing continuously the power button) brings it up.

Kernel: 4.15.0-44-generic, on 18.04.1 LTS (Bionic).

I cannot get anything from dmesg because of the freeze, but some errors from /var/log/syslog that maybe can help:

kernel: [  495.245250] ACPI Error: Method parse/execution failed \_GPE.XTBT, AE_ALREADY_EXISTS (20170831/psparse-550)
...
kernel: [  495.308520] pci 0000:03:00.0: BAR 13: failed to assign [io  size 0x2000]
...
gsd-color[1425]: no xrandr-Dell Inc.-DELL U2417H-5K9YD7AE224L device found: Failed to find output xrandr-Dell Inc.-DELL U2417H-5K9YD7AE224L
...
/usr/lib/gdm3/gdm-x-session[1974]: Errors from xkbcomp are not fatal to the X server
...
systemd-udevd[4191]: Process '/usr/sbin/alsactl -E HOME=/run/alsa restore 1' failed with exit code 99.
...
gnome-shell[1216]: Failed to apply DRM plane transform 0: Permission denied
gnome-shell[1216]: Failed to read EDID from 'eDP-1': No such file or directory
gnome-shell[1216]: message repeated 3 times: [ Failed to read EDID from 'eDP-1': No such file or directory]
gsd-color[1425]: failed to set screen _ICC_PROFILE: Failed to open file â<80><9c>/home/john/.local/share/icc/edid-18e261c7e650a8a483510701873ac4e2.iccâ<80><9d>: Permission denied

Anyone else with the same problem? What do I have to do if this is a general issue to let Ubuntu developers know about it?