Arch Linux

Meurer

Member

Registered: 2015-12-01

Posts: 18

FIFO underrun on pipe A

I have a Dell E6530 running Arch, and I'm using bumblebee. Every time I boot I see the following message:

Jul 28 13:54:17 antonius kernel: [drm:intel_set_cpu_fifo_underrun_reporting [i915]] *ERROR* uncleared fifo underrun on pipe A
Jul 28 13:54:17 antonius kernel: [drm:intel_cpu_fifo_underrun_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun
Jul 28 13:54:17 antonius kernel: [drm:intel_set_pch_fifo_underrun_reporting [i915]] *ERROR* uncleared pch fifo underrun on pch transcoder A
Jul 28 13:54:17 antonius kernel: [drm:intel_pch_fifo_underrun_irq_handler [i915]] *ERROR* PCH transcoder A FIFO underrun

After that Linux boots and works normally (apart from one single flicker that happens on GDM every time).

Why is this happenijng? How can I fix this?

dockland

Member

From: Sweden

Registered: 2015-06-06

Posts: 861

Re: FIFO underrun on pipe A

I googled around a bit and it seem to be a lot of references (even on this forum) that might help you in right direction.
Couldn't find any "static" solution, it seems it's a bug that occurs/reoccurs from time to time with various laptops. There is some workarounds here and there that have fixed it for some people earlier, but perhaps not with your laptop/brand/UEFI.

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Meurer

Member

Registered: 2015-12-01

Posts: 18

Re: FIFO underrun on pipe A

If I disable Intel's IOMMU the error goes away, but I'm still not sure why it happens/what it means.

dockland

Member

From: Sweden

Registered: 2015-06-06

Posts: 861

Re: FIFO underrun on pipe A

Here are some similar bugs/incidents/forum posts that i was browsing through, but as stated, not a clear "solution" often a bug, if i don't misunderstand things, that sometimes have been solved with a kernel upgrade, but, dig for your self

https://bugs.launchpad.net/ubuntu/+sour … ug/1550779
https://bugs.freedesktop.org/show_bug.cgi?id=89518
https://askubuntu.com/questions/840496/ … transcoder
https://bbs.archlinux.org/viewtopic.php?id=214177
https://bugs.freedesktop.org/show_bug.cgi?id=93055

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I possess a device, in my pocket, that is capable of accessing the entirety of information known to man.
I use it to look at funny pictures of cats and to argue with strangers.

R00KIE

Forum Fellow

From: Between a computer and a chair

Registered: 2008-09-14

Posts: 4,734

Re: FIFO underrun on pipe A

That comes from the intel driver and I'm not sure if it's still some driver bug lurking somewhere or because of an hardware bug or limitation. It used to be much worse and manifest itself even your the intel iommu off, as you can probably find by googling for similar problems, and it affected many generations of intel igpus.

That said you really want to disable the iommu for the igpu because if you use it some power saving feature is turned off automatically due to a hardware bug, there is even a message on dmesg about that. You can still use the iommu for everything else though, just use intel_iommu=on,igfx_off in your kernel parameters line.

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R00KIE
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rinzler

Member

Registered: 2017-07-27

Posts: 16

Re: FIFO underrun on pipe A

Mine also showing the same warning message.
I am using Cinnamon as my DE. My system is up to date.
When I entered my password and pressed enter. A flicker happening on my screen.
Is this related to the above problem or something other.
I am adding my comment to this problem because I am getting that flicker problem next to the **FIFO underrun on pipe A** problem started.

R00KIE

Forum Fellow

From: Between a computer and a chair

Registered: 2008-09-14

Posts: 4,734

Re: FIFO underrun on pipe A

I am adding my comment to this problem because I am getting that flicker problem next to the **FIFO underrun on pipe A** problem started.

This is a technical discussion forum, me too and +1 posts are frowned upon here https://wiki.archlinux.org/index.php/Co … mpty_posts

Posting here saying that you also have the same problem does not help get it fixed, open a bug report upstream and make your problem known there.

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R00KIE
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BurhanDanger

Member

From: Sylhet, Bangladesh.

Registered: 2016-09-13

Posts: 29

Re: FIFO underrun on pipe A

For kernel 4.12 onward ( 4.11 works fine ) I get

[drm:intel_set_cpu_fifo_underrun_reporting [i915]] *ERROR* uncleared fifo underrun on pipe A
[drm:intel_cpu_fifo_underrun_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun

Is this related to this problem?

open a bug report upstream and make your problem known there.

What is upstream for Arch Distributed Kernel ? https://bugzilla.kernel.org/ Says    (not distribution kernels)

R00KIE

Forum Fellow

From: Between a computer and a chair

Registered: 2008-09-14

Posts: 4,734

Re: FIFO underrun on pipe A

In the case of the i915 driver you want https://bugs.freedesktop.org/buglist.cg … esolution=--- and for kernel problems you definitely want to go to the kernel bug tracker if the problem is not a packaging problem.

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R00KIE
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leonardof

Member

Registered: 2008-09-05

Posts: 66

Re: FIFO underrun on pipe A

In the case of the i915 driver you want https://bugs.freedesktop.org/buglist.cg … esolution=--- and for kernel problems you definitely want to go to the kernel bug tracker if the problem is not a packaging problem.

https://bugs.freedesktop.org/show_bug.cgi?id=102614