Raspberry Pi 3B+ Constant "Unbalanced enable for IRQ 40" in syslog/ CPU Warning

[Chris Bradford]

I'm running Stretch, with Desktop on a new Pi 3B+ :
> OS Version:March 2018
> Release date:2018-03-13
> Kernel version:4.9
> Up-to-date as of 13:30 GMT 17/03/18

System logs are full of repeating messages, now every second as below. After extended use browsing via Chromium/ using Terminal I keep getting lock-ups on the Pi 3B+ that mean I have to hard reset.

No additional software installed, other than that available via apt-get update/ apt-get dist-upgrade.

Other (potentially?) relevant information:
> Pi is connected to Internet via wireless 5Ghz
> Using a wireless keyboard/ USB RF dongle, however errors persist every second even when I remove the USB dongle
> Using a Bluetooth mouse (see below)
> Disabling Bluetooth makes no difference

------------------------------------------------------------------

Mar 17 12:18:08 raspberrypi kernel: [ 128.956867] ------------[ cut here ]------------
Mar 17 12:18:08 raspberrypi kernel: [ 128.956890] WARNING: CPU: 2 PID: 447 at kernel/irq/manage.c:527 __enable_irq+0x54/0x80
Mar 17 12:18:08 raspberrypi kernel: [ 128.956892] Unbalanced enable for IRQ 40
Mar 17 12:18:08 raspberrypi kernel: [ 128.956894] Modules linked in: fuse rfcomm cmac uhid bnep hci_uart btbcm bluetooth panel_raspberrypi_touchscreen vc4 brcmfmac drm_kms_helper brcmutil drm cfg80211 snd_soc_core snd_compress rfkill snd_pcm_dmaengine syscopyarea sysfillrect sysimgblt fb_sys_fops i2c_gpio snd_bcm2835 i2c_algo_bit snd_pcm snd_timer snd i2c_bcm2835 bcm2835_gpiomem evdev joydev fixed uio_pdrv_genirq uio i2c_dev ip_tables x_tables ipv6
Mar 17 12:18:08 raspberrypi kernel: [ 128.956981] CPU: 2 PID: 447 Comm: Xorg Tainted: G W 4.9.80-v7+ #1098
Mar 17 12:18:08 raspberrypi kernel: [ 128.956983] Hardware name: BCM2835
Mar 17 12:18:08 raspberrypi kernel: [ 128.956999] [<8010fa48>] (unwind_backtrace) from [<8010c058>] (show_stack+0x20/0x24)
Mar 17 12:18:08 raspberrypi kernel: [ 128.957009] [<8010c058>] (show_stack) from [<80457a04>] (dump_stack+0xd4/0x118)
Mar 17 12:18:08 raspberrypi kernel: [ 128.957017] [<80457a04>] (dump_stack) from [<8011d31c>] (__warn+0xf8/0x110)
Mar 17 12:18:08 raspberrypi kernel: [ 128.957025] [<8011d31c>] (__warn) from [<8011d37c>] (warn_slowpath_fmt+0x48/0x50)
Mar 17 12:18:08 raspberrypi kernel: [ 128.957030] [<8011d37c>] (warn_slowpath_fmt) from [<80175da8>] (__enable_irq+0x54/0x80)
Mar 17 12:18:08 raspberrypi kernel: [ 128.957040] [<80175da8>] (__enable_irq) from [<80175e18>] (enable_irq+0x44/0x7c)
Mar 17 12:18:08 raspberrypi kernel: [ 128.957080] [<80175e18>] (enable_irq) from [<7f5c4c40>] (vc4_irq_postinstall+0x24/0x40 [vc4])
Mar 17 12:18:08 raspberrypi kernel: [ 128.957129] [<7f5c4c40>] (vc4_irq_postinstall [vc4]) from [<7f5c78f0>] (vc4_v3d_runtime_resume+0x58/0x60 [vc4])
Mar 17 12:18:08 raspberrypi kernel: [ 128.957161] [<7f5c78f0>] (vc4_v3d_runtime_resume [vc4]) from [<8050391c>] (pm_generic_runtime_resume+0x3c/0x48)
Mar 17 12:18:08 raspberrypi kernel: [ 128.957170] [<8050391c>] (pm_generic_runtime_resume) from [<80507724>] (__genpd_runtime_resume+0x3c/0x9c)
Mar 17 12:18:08 raspberrypi kernel: [ 128.957177] [<80507724>] (__genpd_runtime_resume) from [<805091f4>] (genpd_runtime_resume+0xd8/0x1a4)
Mar 17 12:18:08 raspberrypi kernel: [ 128.957184] [<805091f4>] (genpd_runtime_resume) from [<80504eb4>] (__rpm_callback+0x48/0x98)
Mar 17 12:18:08 raspberrypi kernel: [ 128.957189] [<80504eb4>] (__rpm_callback) from [<80504f34>] (rpm_callback+0x30/0x90)
Mar 17 12:18:08 raspberrypi kernel: [ 128.957194] [<80504f34>] (rpm_callback) from [<80506320>] (rpm_resume+0x4bc/0x704)
Mar 17 12:18:08 raspberrypi kernel: [ 128.957202] [<80506320>] (rpm_resume) from [<805065d8>] (__pm_runtime_resume+0x70/0x9c)
Mar 17 12:18:08 raspberrypi kernel: [ 128.957229] [<805065d8>] (__pm_runtime_resume) from [<7f5c178c>] (vc4_submit_cl_ioctl+0x160/0x954 [vc4])
Mar 17 12:18:08 raspberrypi kernel: [ 128.957390] [<7f5c178c>] (vc4_submit_cl_ioctl [vc4]) from [<7f3dec60>] (drm_ioctl+0x20c/0x428 [drm])
Mar 17 12:18:08 raspberrypi kernel: [ 128.957500] [<7f3dec60>] (drm_ioctl [drm]) from [<80283f68>] (do_vfs_ioctl+0xac/0x820)
Mar 17 12:18:08 raspberrypi kernel: [ 128.957509] [<80283f68>] (do_vfs_ioctl) from [<80284720>] (SyS_ioctl+0x44/0x6c)
Mar 17 12:18:08 raspberrypi kernel: [ 128.957517] [<80284720>] (SyS_ioctl) from [<801080c0>] (ret_fast_syscall+0x0/0x1c)
Mar 17 12:18:08 raspberrypi kernel: [ 128.957520] ---[ end trace 0064cd54f2f57c0a ]---

[Chris Bradford (kiwi88)]

I've established that this is being caused by OpenGL being enabled - I had enabled this in "G1 GL (Full KMS)" mode. When running in "G3 Legacy" I do not get these events in the syslog.

[Chris Bradford (kiwi88)]

Also confirmed that this issue occurs under the "G2 GL (Fake KMS)" mode.

[James McGuire (mcguire-clan)]

Confirmed, I am getting the same flood of trace dumps when using Xwayland on Raspberry Pi 3b with dtoverlay=vc4-kms-v3d enabled, after updating kernel to 4.9.80-v7.

 I also filled an issue on github:
[Xwayland Tainted: 4.9.80-v7+](https://github.com/raspberrypi/linux/issues/2448)

[Doug Coulter (dcfusor)]

I'm seeing a more-general issue here. Things (tightvncserver, conky) autostarted by almost any method (rc.local, .profile, systemD) get started in a loop forever till memory and CPU are 100% and it locks up and gets very hot.
Something basic wrong?

[Jernej Jakob (jjakob)]

Can confirm, happens as long as there is activity in X (even moving a window around is enough).
Running openbox on xserver-xorg with GL driver enabled.

[Oisín Mac Fhearaí (denpashogai)]

Seeing exactly the same stacktrace here, repeated in syslog, messages and kern.log which all grew to over 800 mb and caused the root partition to run out of space. This is pretty bad since the Pi becomes completely unusable for kids -- they asked me to help because logging in at the X login prompt just causes a black screen and brings them back to the login prompt.

[Oisín Mac Fhearaí (denpashogai)]

Update: I did a dist-upgrade and got kernel version 4.14.34-v7+ which so far seems OK.