[Bug 1948894] Re: Xwayland crash in gdm as screen off and touchscreen detach.

Tue Nov 9 09:34:11 UTC 2021

I try to install impish and hirsute on the target machine, with the
kernel from focal (so that it support the new ADL GPU, and then the
monitor can be turned off so that the touchscreen will be detached,
that's the way we reproduce this issue in focal)

With that, with or without mutter from the proposed channel, I can't
reproduce this issue. (We do see the backlight turned off and the
touchscreen detached from kernel message.)

Given this is a timing-sensitive issue, I think as long as there is no
regression, then we can call that as verified done.

I've dog food those, and can't find regression so far. So I'll tag
verify done.

** Tags removed: verification-needed verification-needed-hirsute verification-needed-impish
** Tags added: verification-done verification-done-hirsute verification-done-impish

-- 
You received this bug notification because you are a member of Ubuntu
Sponsors Team, which is subscribed to the bug report.
https://bugs.launchpad.net/bugs/1948894

Title:
  Xwayland crash in gdm as screen off and touchscreen detach.

Status in Mutter:
  Unknown
Status in OEM Priority Project:
  Fix Committed
Status in mutter package in Ubuntu:
  Fix Released
Status in mutter source package in Focal:
  Fix Committed
Status in mutter source package in Hirsute:
  Fix Committed
Status in mutter source package in Impish:
  Fix Committed

Bug description:
  [Impact]

   * Gdm crashed and user need to be an expert to know how to work around,
     or need to reboot to fix.

   * OEM projects got certain SKU that can reliably reproduce this
  issue.

   * A merged patch in upstream fix the race condition.

  [Test Plan]

   * Use the SKU that can reliably reproduce this issue.
   * Do a cold boot, and wait for 5 mins. The monitor should turned-black
     but showing the Machine Vendor logo that was previously
     displayed by plymouth.
   * Try to dog-food the deb from the proposed channel and make sure
     all input events still properly propagate.

  [Where problems could occur]

   * If the patch is not properly working as expected, per the file this
     patch touch, the user desktop session could stop responding to
     mouse, keyboard, and touch screen input.

  [Other Info]

   * Can't think of any for now.

  ----

  This is a reproducible issue. Step to reproduce
  1. cold boot into gdm login screen.
  2. wait for 5 mins, and the screen will be turned off. (also observed that the touchscreen USB device drop of a USB bus on the target machine)

  Note: this bug seems to be timing sensitive. I got an OEM project
  machine that can reproduce this issue (reproducible on several
  machines with the same HW design). The machine is using ADL CPU, which
  needs a patched 5.14 kernel. So I can't reproduce this on impish. With
  the backported mutter, I verified an upstream patch seems to fix this
  issue.

  Expected result:
  The screen just turns black.

  Actual result:
  Saw Vendor boot logo on the monitor (previous draw by plymouth during booting)

  Analysis as it happens:
  1. Saw "LGDisplay Incell Touch" drop off the USB bus.
     Kernel message like: "usb 1-9: USB disconnect, device number 6"
     as the screen turned black.
  2. There is no switch on virtual tty.
  3. journal log from Xwayland "wl_display at 1: error 0: invalid object 24"
  4. Xwayland and gnome-shell process both die as this happens.
  5. Try to add sleep(30) to OsVendorFatalError(), then both Xwayland and
     gnome-shell stop there for 30 more seconds.
  6. backtrace as Xwayland crashed:

  ```
  #0 0x00007f447b8e818b in raise () from /lib/x86_64-linux-gnu/libc.so.6
  #1 0x00007f447b8c7859 in abort () from /lib/x86_64-linux-gnu/libc.so.6
  #2 0x0000564374403f30 in OsAbort () at ../../../../os/utils.c:1351
  #3 0x0000564374409369 in AbortServer () at ../../../../os/log.c:872
  #4 0x000056437440a1ca in FatalError (f=f at entry=0x564374416266 "%s") at ../../../../os/log.c:1010
  #5 0x000056437429c8b0 in xwl_log_handler (format=<optimized out>, args=<optimized out>) at ../../../../../hw/xwayland/xwayland.c:1312
  #6 0x00007f447c3d027e in wl_log (fmt=fmt at entry=0x7f447c3d121a "%s@%u: error %d: %s\n") at ../src/wayland-util.c:404
  #7 0x00007f447c3cb78b in display_handle_error (data=<optimized out>, display=0x56437639f000, object=0x56437639f000, code=0, message=<optimized out>)
      at ../src/wayland-client.c:911
  #8 0x00007f447b7c0ff5 in ?? () from /lib/x86_64-linux-gnu/libffi.so.7
  #9 0x00007f447b7c040a in ?? () from /lib/x86_64-linux-gnu/libffi.so.7
  #10 0x00007f447c3cf3a8 in wl_closure_invoke (closure=closure at entry=0x564376e57350, flags=flags at entry=1, target=<optimized out>,
      target at entry=0x56437639f000, opcode=opcode at entry=0, data=<optimized out>) at ../src/connection.c:1018
  #11 0x00007f447c3cbc48 in dispatch_event (display=display at entry=0x56437639f000, queue=<optimized out>) at ../src/wayland-client.c:1445
  #12 0x00007f447c3cd1ef in dispatch_queue (queue=0x56437639f0d0, display=0x56437639f000) at ../src/wayland-client.c:1584
  #13 wl_display_dispatch_queue_pending (display=0x56437639f000, queue=0x56437639f0d0) at ../src/wayland-client.c:1833
  #14 0x00007f447c3cd280 in wl_display_dispatch_pending (display=<optimized out>) at ../src/wayland-client.c:1896
  #15 0x000056437429c9bb in xwl_read_events (xwl_screen=0x564376399dd0) at ../../../../../hw/xwayland/xwayland.c:957
  #16 0x0000564374401c61 in ospoll_wait (ospoll=0x56437638f4a0, timeout=<optimized out>) at ../../../../os/ospoll.c:657
  #17 0x00005643743faa23 in WaitForSomething (are_ready=0) at ../../../../os/WaitFor.c:208
  #18 0x00005643743ca4a7 in Dispatch () at ../../../../include/list.h:220
  #19 0x00005643743ce794 in dix_main (argc=16, argv=0x7ffc44d49298, envp=<optimized out>) at ../../../../dix/main.c:276
  #20 0x00007f447b8c90b3 in __libc_start_main () from /lib/x86_64-linux-gnu/libc.so.6
  #21 0x000056437429c60e in _start ()```

To manage notifications about this bug go to:
https://bugs.launchpad.net/mutter/+bug/1948894/+subscriptions