# IRQ disabled?

## The_Great_Sephiroth

I was working with certificates in a console window in Plasma when this popped up in the console window.

```

Message from syslogd@9y84mj1 at Fri Aug 24 15:38:12 2018 ...

9y84mj1 kernel: [17131.992007] Disabling IRQ #16

```

Now the entire system is running SLOWLY. I can out-type the cursor in this window, for example. What is going on here? I never saw this before. I know a reboot can fix it, but why did it happen?

*EDIT*

It looks like IRQ16 is my video card. What the heck?

```

           CPU0       CPU1       

  0:   23679984    6277546   IO-APIC   2-edge      timer

  1:      17181       6307   IO-APIC   1-edge      i8042

  8:          7          4   IO-APIC   8-edge      rtc0

  9:       8958        701   IO-APIC   9-fasteoi   acpi

 12:     333471     169596   IO-APIC  12-edge      i8042

 16:   71854699   70645301   IO-APIC  16-fasteoi   i915

 17:          9          1   IO-APIC  17-fasteoi   firewire_ohci

 18:          0          0   IO-APIC  18-fasteoi   mmc0, mmc1

 19:          0          0   IO-APIC  19-fasteoi   i801_smbus

 20:          0          0   IO-APIC  20-fasteoi   ehci_hcd:usb2, uhci_hcd:usb3, uhci_hcd:usb6

 21:          0          0   IO-APIC  21-fasteoi   uhci_hcd:usb4, uhci_hcd:usb7

 22:        120         17   IO-APIC  22-fasteoi   ehci_hcd:usb1, uhci_hcd:usb5, uhci_hcd:usb8

 24:          0          0  DMAR-MSI   0-edge      dmar0

 25:          0          0  DMAR-MSI   2-edge      dmar2

 26:     476257      77552   PCI-MSI 512000-edge      ahci[0000:00:1f.2]

 27:         45         47   PCI-MSI 442368-edge      snd_hda_intel:card0

 28:     671304     317520   PCI-MSI 6291456-edge      iwlwifi

 29:          0        221   PCI-MSI 409600-edge      enp0s25

NMI:          0          0   Non-maskable interrupts

LOC:    6536207   20697960   Local timer interrupts

SPU:          0          0   Spurious interrupts

PMI:          0          0   Performance monitoring interrupts

IWI:    1502354    1516057   IRQ work interrupts

RTR:          0          0   APIC ICR read retries

RES:    1128235    1410100   Rescheduling interrupts

CAL:      36028      35893   Function call interrupts

TLB:      34799      34727   TLB shootdowns

TRM:          0          0   Thermal event interrupts

THR:          0          0   Threshold APIC interrupts

MCE:          0          0   Machine check exceptions

MCP:         58         57   Machine check polls

ERR:          0

MIS:          0

PIN:          0          0   Posted-interrupt notification event

NPI:          0          0   Nested posted-interrupt event

PIW:          0          0   Posted-interrupt wakeup event

```

----------

## The_Great_Sephiroth

I am still not sure what caused this. It may have been due to a weak charge (battery getting low), but I verified that IRQ16 is indeed, the video card. When it disables, framerates drop into the sewer. Is there a way to tell the kernel to not disable my video card even when on low power?

----------

## Jaglover

Why you think kernel disables the IRQ? IRQ is in hardware, kernel cannot use it if it gets disabled.

----------

## P.Kosunen

Do you have "options i2c-i801 disable_features=0x10" set under /etc/modprobe.d/?

```
$ dmesg | grep -i smbus

[    1.476403] i801_smbus 0000:00:1f.4: Interrupt disabled by user

[    1.476544] i801_smbus 0000:00:1f.4: SMBus using polling
```

----------

## The_Great_Sephiroth

Unless it is set by default, I do not have it set. I have never had to mess with IRQ settings before.

Jag, I believe it is the kernel due to the message in my first post. I'm chilling there and then "9y84mj1 kernel: [17131.992007] Disabling IRQ #16" pops up. You know, it even says "kernel" sent the message, so if the kernel did not disable the IRQ as the message states, then I am thoroughly confused!

----------

## Jaglover

It may be, but it is also possible kernel is merely letting you to know the IRQ has been disabled in hardware.

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## The_Great_Sephiroth

Well, prior to using Debian and after that, Gentoo on this system, Windows never had the issue. This is indeed the first time it happened even in Linux, but only after a recent update. I imagine something changed to conserve power and it doesn't like doing that on my system. Either way, how do I troubleshoot or resolve this issue?

----------

## Jaglover

Hardware ages, what was working yesterday may not work tomorrow.

There are debug options in kernel, enabling debug produces more verbose kernel log.

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## The_Great_Sephiroth

This isn't hardware, I am 99.9% sure of that. I don't want to change my kernel for this, I just want to figure out what does it. If I need a debug kernel and all that, it isn't worth messing with. I actually use this system. Quite heavily, in fact.

I did just do a new search with a few words changed and apparently this is an old issue. It's all over the place. Doubt it is my hardware due to this. Will search more when time permits.

----------

## tholin

 *The_Great_Sephiroth wrote:*   

> I did just do a new search with a few words changed and apparently this is an old issue. It's all over the place. Doubt it is my hardware due to this. Will search more when time permits.

 

Most of those problems look like the same thing. Some device is broken and have a stuck interrupt. The kernel will notice this ("nobody cared") and disable interrupts for that device and instead poll it a few times per second. There was an old Asmedia PCIe-PCI bridge that was infamous for having this problem.

----------

## CooSee

did you try with any other live-cd, if this still exist ?

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## Ant P.

This isn't hardware failure. The intel graphics driver isn't great, it's been this way for a long time. One of the workarounds they added many years ago is a hang detector that forces it into dumb framebuffer mode instead of crashing entirely, that's what's happening in this case. No idea what the cause is, but rebooting will fix it. Or maybe power-cycling the hardware - try suspending?

Sometimes the cure is worse than the disease, though; this used to be a daily occurrence on my netbook around 2011-12, but I barely noticed when it happened because I run Openbox and the GPU was already slow. Running KDE's compositor without 3D acceleration is going to sting.

----------

## The_Great_Sephiroth

I believe Ant hit the nail on the head. This was indeed my graphics card. After I got hibernation working I was hibernating it or suspending it all week between client locations. Basically, I'd suspend it, drive to wherever, wake it up, work, and repeat. At the end of the day I'd suspend it so I could pick up where I left off Monday. I started it up one Monday and after about ten minutes it did this. My guess is that the driver had been "up" for too long and screwed up. Will try this again to see if it is reproducible. If it is, I can narrow it down to the driver not liking to be loaded all week. It has not done this since, but I am also back to shutting down every day.

----------

## The_Great_Sephiroth

Just following up here. It happened AGAIN. I was in Plasma and I only had VirtualBox open (DOS 6.22 w/WFW3.11) and Chromium. Suddenly DOS got slow (DOS was NEVER slow) and when I went back to Plasma, slow as heck. I shutdown the VM and rebooted and when the desktop disappeared and it went to the shell, I saw it had disabled IRQ #16 again.

This is most likely a kernel issue at this point. I did NOT have this issue in 4.14.52, but it is rampant in 4.14.65. I imported the old configuration with "make oldconfig" as always, so it is an identical configuration. Not sure what it is, but something in the new kernel is flaky.

----------

## tholin

 *The_Great_Sephiroth wrote:*   

> I did NOT have this issue in 4.14.52, but it is rampant in 4.14.65.

 

It should be easy to git-bisect then. My bet would be on this patch in 4.14.58.

https://patchwork.freedesktop.org/patch/229559/

It changes how the kernel handles interrupts of hotplug events (hotplugging of monitors). That patch only apply to some older IGPUs. What hardware do you have anyway?

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## The_Great_Sephiroth

It is an older Dell latitude E6400 system off the top of my head. Core2Duo, 8GB RAM, 1TB SATA2 disk, DVD-RAM drive, smart-chip reader, the whole nine yards. Next time I use it I will post the specifics. I use the i965 driver.

----------

## tholin

https://www.cnet.com/products/dell-latitude-e6400-14-1-core-2-duo-p8700-vista-business-xp-pro-downgrade-2-gb-ram-160-gb-hdd-series/specs/

According to this site the Dell latitude E6400 use an Intel GMA 4500MHD which is an i965/g4x (fourth generation IGPU) so that patch is active. Try reverting it an see if the problem goes away.

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## The_Great_Sephiroth

I'm not hot-plugging though. I rarely use a second monitor these days and I rely on the one on the laptop itself 99% of the time.

----------

## Maitreya

 *The_Great_Sephiroth wrote:*   

> I'm not hot-plugging though. I rarely use a second monitor these days and I rely on the one on the laptop itself 99% of the time.

 

I think some close/open lid actions are implemented as (un)plug

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## The_Great_Sephiroth

That could possibly be it, except the most recent occurrence happened without any lid action going on. It simply disabled the IRQ while I was working with a virtual machine.

----------

