Greg KH wrote:
On Sat, Nov 18, 2017 at 01:47:32PM +0100, Rainer Fiebig wrote:
Hi!
Hopefully the right addressee.
Encountered two bad backports which cause screen-flicker. dmesg shows:
... [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder A FIFO underrun [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe B FIFO underrun [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder B FIFO underrun ...
CPU: Intel Core i3 (Clarkdale/Ironlake)
The backports are:
- diff --git a/drivers/gpu/drm/i915/intel_pm.c
b/drivers/gpu/drm/i915/intel_pm.c index 49de476..277a802 100644
- diff --git a/drivers/gpu/drm/i915/intel_drv.h
b/drivers/gpu/drm/i915/intel_drv.h index a19ec06..3ce9ba3 100644
After reversing them the flicker is gone, no more messages in dmesg. All else OK so far.
So which commit was the one that caused the problem? I will be glad to revert it.
thanks,
greg k-h
I started by reverting the more complex one first ("index 49de476..277a802100644"). But the kernel wouldn't compile then.
So I also reverted "index a19ec06..3ce9ba3 100644". After that the kernel compiled just fine and the problems were gone (still are).
I haven't yet tried it vice versa - it was a bit late yesterday. But I'll give it a try somewhat later today and let you know.
Personally, I could live without *both* of them.
So long! Rainer Fiebig