[gentoo-user] Strange behaviour disconnecting and reconnecting USB-C screen

[gentoo-user] Strange behaviour disconnecting and reconnecting USB-C screen

[Andreas Fink]

Hello,
I've got a new laptop and see a strange behaviour when disconnecting
and reconnecting my USB-C screen.
Here are the steps that I am doing. I have a dual screen setup with
xrandr, with my notebook screen being the primary screen and a second
large external screen connected via USB-C to my notebook directly.
Now I disconnect the USB-C cable and do not do anything software wise,
i.e. my X-Server is still pretending to run on two screens, I can move
the screen outside of my notebook screen (into the area where the
external screen).
Now I reconnect the USB-C cable but the screens stays blank (the the
screen it says "No USB Type-C connection from your computer"). The only
way to get a signal again is to first use xrandr to only use my
notebook screen, and at the exact time udev gets a DRM event, and
suddently my external monitor appears within xrandr as connected (I did
not touch the cable, I only ran an xrandr command to use only the
notebook screen). Right after the DRM event I can run the xrandr
command to use both screens, but it is annoying to degrade first to one
screen, because all windows are moved around and I do not end up with
the same window setup as before.

Using the same screen with the same experiment as described above but
with a different notebook the screen is able to pick up the signal
again, so it's not purely a problem with the external screen.
Any idea what is going on and how I can workaround it? I just want to
disconnect the cable and reconnect it without the need to switch any
xrandr setup.

Thanks for your ideas and help
Andreas

Re: [gentoo-user] Strange behaviour disconnecting and reconnecting USB-C screen

[Benjamin Blanz]

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Hi,
I have the same issue using a usb-c dockingstation.
I have found it is enough to change the resolution of the connected screens to get them back.
Still annoying, but at least the windows are not redistributed.On 11.01.22 10:25, Andreas Fink wrote:

> Hello,
> I've got a new laptop and see a strange behaviour when disconnecting
> and reconnecting my USB-C screen.
> Here are the steps that I am doing. I have a dual screen setup with
> xrandr, with my notebook screen being the primary screen and a second
> large external screen connected via USB-C to my notebook directly.
> Now I disconnect the USB-C cable and do not do anything software wise,
> i.e. my X-Server is still pretending to run on two screens, I can move
> the screen outside of my notebook screen (into the area where the
> external screen).
> Now I reconnect the USB-C cable but the screens stays blank (the the
> screen it says "No USB Type-C connection from your computer"). The only
> way to get a signal again is to first use xrandr to only use my
> notebook screen, and at the exact time udev gets a DRM event, and
> suddently my external monitor appears within xrandr as connected (I did
> not touch the cable, I only ran an xrandr command to use only the
> notebook screen). Right after the DRM event I can run the xrandr
> command to use both screens, but it is annoying to degrade first to one
> screen, because all windows are moved around and I do not end up with
> the same window setup as before.
> 
> Using the same screen with the same experiment as described above but
> with a different notebook the screen is able to pick up the signal
> again, so it's not purely a problem with the external screen.
> Any idea what is going on and how I can workaround it? I just want to
> disconnect the cable and reconnect it without the need to switch any
> xrandr setup.
> 
> Thanks for your ideas and help
> Andreas
> 

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Re: [gentoo-user] Strange behaviour disconnecting and reconnecting USB-C screen

[Andreas Fink]

On Tue, 11 Jan 2022 10:57:28 +0100
Benjamin Blanz <benjamin.blanz@gmx.de> wrote:

> Hi,
> I have the same issue using a usb-c dockingstation.
> I have found it is enough to change the resolution of the connected screens to get them back.
> Still annoying, but at least the windows are not redistributed.On 11.01.22 10:25, Andreas Fink wrote:
>
That did not work for me because xrandr complains that any resolution
is an unknown mode.
Which command do you use to change the resolution of the connected
screen?

Re: [gentoo-user] Strange behaviour disconnecting and reconnecting USB-C screen

[Benjamin Blanz]

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My normal layout
#!/bin/sh
xrandr --output eDP-1 --mode 1920x1080 --pos 3640x249 --rotate normal --output DP-1 --off --output HDMI-1 --off --output DP-2 --off --output HDMI-2 --off --output DP-1-1 --mode 1920x1080 --pos 0x0 --rotate left --output DP-1-2 --off --output DP-1-2-8 --primary --mode 2560x1600 --pos 1080x46 --rotate normal --output DP-1-2-1 --off --output DP-1-3 --off

The layout I switch to to wake the screens up, before then switchign back to the normal layout
#!/bin/sh
xrandr --output eDP-1 --mode 1920x1080 --pos 3640x498 --rotate normal --output DP-1 --off --output HDMI-1 --off --output DP-2 --off --output HDMI-2 --off --output DP-1-1 --mode 1600x1200 --pos 0x0 --rotate left --output DP-1-2-8 --primary --mode 1920x1600 --pos 1080x46 --rotate normal --output DP-1-2-1 --off --output DP-1-2 --off --output DP-1-3 --off

I used arandr to generate the commands and have the assigned to hotkeys

On 11.01.22 12:13, Andreas Fink wrote:
> On Tue, 11 Jan 2022 10:57:28 +0100
> Benjamin Blanz <benjamin.blanz@gmx.de> wrote:
> 
>> Hi,
>> I have the same issue using a usb-c dockingstation.
>> I have found it is enough to change the resolution of the connected screens to get them back.
>> Still annoying, but at least the windows are not redistributed.On 11.01.22 10:25, Andreas Fink wrote:
>>
> That did not work for me because xrandr complains that any resolution
> is an unknown mode.
> Which command do you use to change the resolution of the connected
> screen?
> 

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Re: [gentoo-user] Strange behaviour disconnecting and reconnecting USB-C screen

[ny6p01]

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What I would do is create a bash script and link to a keyboard shortcut to
execute as needed. One of the advantages of xrandr is the ease of scripting.


Lee 😎

On Jan 11, 2022 at 1:25 AM, Andreas Fink <finkandreas@web.de> wrote:

Hello,
I've got a new laptop and see a strange behaviour when disconnecting
and reconnecting my USB-C screen.
Here are the steps that I am doing. I have a dual screen setup with
xrandr, with my notebook screen being the primary screen and a second
large external screen connected via USB-C to my notebook directly.
Now I disconnect the USB-C cable and do not do anything software wise,
i.e. my X-Server is still pretending to run on two screens, I can move
the screen outside of my notebook screen (into the area where the
external screen).
Now I reconnect the USB-C cable but the screens stays blank (the the
screen it says "No USB Type-C connection from your computer"). The only
way to get a signal again is to first use xrandr to only use my
notebook screen, and at the exact time udev gets a DRM event, and
suddently my external monitor appears within xrandr as connected (I did
not touch the cable, I only ran an xrandr command to use only the
notebook screen). Right after the DRM event I can run the xrandr
command to use both screens, but it is annoying to degrade first to one
screen, because all windows are moved around and I do not end up with
the same window setup as before.

Using the same screen with the same experiment as described above but
with a different notebook the screen is able to pick up the signal
again, so it's not purely a problem with the external screen.
Any idea what is going on and how I can workaround it? I just want to
disconnect the cable and reconnect it without the need to switch any
xrandr setup.

Thanks for your ideas and help
Andreas

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