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 > OK, when reversing only "index 49de476..277a802 100644" the kernel doesn't compile. When reversing only "index a19ec06..3ce9ba3 100644" the kernel compiles but the flicker is there. Seems those patches are a nasty couple that needs to be removed as such. ;) So long! Rainer Fiebig