Bug 100143 - [SNB] i915 4.11.0-rc1 circular locking dependency detected, switcheroo-cont/776 is trying to acquire lock
Summary: [SNB] i915 4.11.0-rc1 circular locking dependency detected, switcheroo-cont/7...
Status: RESOLVED MOVED
Alias: None
Product: DRI
Classification: Unclassified
Component: DRM/Radeon (show other bugs)
Version: unspecified
Hardware: Other All
: medium normal
Assignee: Default DRI bug account
QA Contact:
URL:
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2017-03-09 22:47 UTC by Chris Murphy
Modified: 2019-11-19 09:26 UTC (History)
3 users (show)

See Also:
i915 platform: SNB
i915 features:


Attachments
journal konly 4.11.0-rc1+debug drm.debug=0x1e (551.97 KB, text/x-log)
2017-03-09 22:47 UTC, Chris Murphy
no flags Details
journal konly 4.13.0-rc1 (334.57 KB, text/plain)
2017-07-18 03:58 UTC, Chris Murphy
no flags Details

Description Chris Murphy 2017-03-09 22:47:07 UTC
Created attachment 130151 [details]
journal konly 4.11.0-rc1+debug drm.debug=0x1e

During boot, an INFO message pops up shortly after switcheroo-control.service is started.


BOOT_IMAGE=/vmlinuz-4.11.0-0.rc1.git0.1.fc26.x86_64+debug root=UUID=15910530-9840-49af-b948-34eb9599442e ro rootflags=subvol=root00 elevator=deadline drm.debug=0x1e enforcing=0

[    7.670365] localhost.localdomain kernel: snd_hda_intel 0000:01:00.1: Disabling via vga_switcheroo
[    7.673522] localhost.localdomain kernel: 
[    7.673522] localhost.localdomain kernel: ======================================================
[    7.673523] localhost.localdomain kernel: [ INFO: possible circular locking dependency detected ]
[    7.673524] localhost.localdomain kernel: 4.11.0-0.rc1.git0.1.fc26.x86_64+debug #1 Not tainted
[    7.673525] localhost.localdomain kernel: -------------------------------------------------------
[    7.673525] localhost.localdomain kernel: switcheroo-cont/776 is trying to acquire lock:
[    7.673526] localhost.localdomain kernel:  (console_lock){+.+.+.}, at: [<ffffffffba631389>] vga_switchto_stage2+0x99/0x130
[    7.673532] localhost.localdomain kernel: 
                                             but task is already holding lock:
[    7.673532] localhost.localdomain kernel:  (vgasr_mutex){+.+.+.}, at: [<ffffffffba631a4a>] vga_switcheroo_debugfs_write+0x8a/0x3f0
[    7.673535] localhost.localdomain kernel: 
                                             which lock already depends on the new lock.
Comment 1 Bastien Nocera 2017-06-30 09:38:45 UTC
The locking backtrace shows the problem between the radeon driver and the tty/fbcon ones, not the Intel driver.

Switcheroo-control disables the discrete GPU during bootup, so that only the Intel/integrated GPU is enabled by default.

https://github.com/hadess/switcheroo-control/blob/master/src/switcheroo-control.c#L223
would be roughly equivalent to:
echo DIGD > /sys/kernel/debug/vgaswitcheroo/switch
as root.
Comment 2 Chris Murphy 2017-07-18 03:58:15 UTC
Created attachment 132741 [details]
journal konly 4.13.0-rc1

Same hardware, different kernel, same 'possible circular locking dependency detected' message but different instigator, this time it's consistently saying 'plymouthd/363 is trying to acquire lock'

drm.debug=0x1e enabled, is a debug kernel
Comment 3 Martin Peres 2019-11-19 09:26:19 UTC
-- GitLab Migration Automatic Message --

This bug has been migrated to freedesktop.org's GitLab instance and has been closed from further activity.

You can subscribe and participate further through the new bug through this link to our GitLab instance: https://gitlab.freedesktop.org/drm/amd/issues/782.


Use of freedesktop.org services, including Bugzilla, is subject to our Code of Conduct. How we collect and use information is described in our Privacy Policy.