Display and Softlock Issues after using HDMI through USB Hub

MNT Pocket Reform
1

Last night I tried using a usb-c to HDMI adapter to connect my Pocket to a TV (it did not work, I believe because I did not use wlr-randr or sway output to set it up, but maybe because of the adapter)

Since doing this, two issues have emerged.

PXL_20250510_161240117.MP
PXL_20250510_161240117.MP901×1201 218 KB

  1. Display Issue
  • A second monitor is active at boot
  • Only the rightmost portion of the display is used during boot [pictured]
  • After starting sway, a second monitor is active (a workspace is there and I can move windows to and from it). This is fixed by disabling the output in sway or wlr-randr, but all other issues persist.
  1. Soft Locks
  • I thought these were hard locks but logging into a terminal instead of sway, I occasionally see:
    watchdog: BUG: softlockup - CPU#4 stuck for 49s! [snapd:1010]
  • Sometimes this time is longer or shorter.

I’m still very green with linux. The closest I’ve come to a hint is that this may be related to tty and framebuffer, but I haven’t modified the kernel at all, only plugged an HDMI into the (wrong?) port.

Note The failed message during boot is apparmor service profiles. I can’t remember if that was happening before this or not.

1 Like
2

I cannot help but notice that your display looks like the one in the photo by @ewolff posted here: Problems with display and clock

Since you are the second person with that issue, let me ping @minute for input. Maybe they can help!

3 Likes
3

  1. I believe display output through the usb-c port is not supported by hardware, isn’t it?

  2. Those display problems are caused by the 6.14 kernel.
    After upgrading to 6.14, /sys/class/drm/card1-HDMI-A-1/status indicates connected even though I have no external displays connected.

2 Likes
4

Ah, that makes sense. Thanks for pointing it out!

2 Likes
5

Sorry, this is a bug that I introduced when cleaning up the patches and DTS files for the new kernel. I didn’t notice it during (extensive) testing because my Pocket Reform was connected to HDMI during testing, and the problem manifests when HDMI is not connected. I forgot to port over the correct pinctrl for the hotplug pin (HPD). This should be fixed once this is through CI and merged:

6 Likes