Hi, Using Linux 4.2 on a new Skylake laptop, I frequently see the internal display go momentarily black, with a coinciding message in the logs: [drm:intel_cpu_fifo_underrun_irq_handler] *ERROR* CPU pipe A FIFO underrun Testing linus master, the problem is gone. Does anyone know what commit might have fixed this? I would like to backport to 4.2. I already tried cherry-picking the patches that mention skl that apply trivially, and while that fixed some GPU hangs I was seeing, the FIFO underrun is still present with 4.2 plus: drm/i915/skl: Retrieve the Rpe value from Pcode drm/i915/skl: WaIgnoreDDIAStrap is forever, always init DDI A drm/i915/skl WaDisableSbeCacheDispatchPortSharing drm/i915:skl: Add WaEnableGapsTsvCreditFix drm/i915/skl: Restrict the ring frequency table programming to SKL drm/i915/skl: Ring frequency table programming changes drm/i915/skl: Don't warn if reading back DPLL0 is disabled drm/i915: Move WaBarrierPerformanceFixDisable:skl to skl code from chv code drm/i915/skl: Don't try to store the wrong central frequency drm/i915/skl: Remove unnecessary () used with abs_diff() drm/i915/skl: Remove unnecessary () used with div_u64() drm/i915/skl: Factor out computing the DPLL paramaters from the dividers drm/i915/skl: Use a more idomatic early return drm/i915/skl: Propagate the error if we fail to find a suitable DPLL divider drm/i915/skl: Display the WRPLL frequency we couldn't accomodate when failing drm/i915/skl: Make sure to break when not finding suitable PLL dividers Hardware: 00:02.0 VGA compatible controller [0300]: Intel Corporation Device [8086:1916] (rev 07) (prog-if 00 [VGA controller]) Subsystem: ASUSTeK Computer Inc. Device [1043:1c3d] Flags: bus master, fast devsel, latency 0, IRQ 16 Memory at de000000 (64-bit, non-prefetchable) [size=16M] Memory at c0000000 (64-bit, prefetchable) [size=256M] I/O ports at f000 [size=64] Expansion ROM at <unassigned> [disabled] Capabilities: [40] Vendor Specific Information: Len=0c <?> Capabilities: [70] Express Root Complex Integrated Endpoint, MSI 00 Capabilities: [ac] MSI: Enable- Count=1/1 Maskable- 64bit- Capabilities: [d0] Power Management version 2 Capabilities: [100] #1b Capabilities: [200] Address Translation Service (ATS) Capabilities: [300] #13 Kernel driver in use: i915 Thanks Daniel _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
