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  1. Bug #1727662
  2. Comment #75

Comment 75 for bug 1727662

Revision history for this message
In , Lakshminarayana-vudum (lakshminarayana-vudum) wrote :

(In reply to Johan Thorén from comment #19)
> This error still occurs on kernel 4.20.
>
> My model is T470s and the behavior is consistent: It only happens when
> connected to an external display through the dock, not when using it
> disconnected from the dock. Can (most of the time) be triggered by changing
> display settings through xrandr.
>
> Dock model is SD20F82750.
>
> Dmesg error message:
> [drm:intel_cpu_fifo_underrun_irq_handler [i915]] *ERROR* CPU pipe B FIFO
> underrun
>
> GPU: Intel Corporation Skylake GT2 [HD Graphics 520] (rev 07)

The original bug is reported is on Broadwell. So, your issue could be different from the original issue reported in this bug.

Can you please attach the full dmesg log from boot with kernel parameters drm.debug=0x1e log_buf_len=4M?

What is the impact of this issue other than the error in the log? Can you elaborate the issue?