DMAR:[fault reason 02] Present bit in context entry is clear (firewire-ohci)
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From: Matthew Wilcox on 22 May 2010 08:20 On Sat, May 22, 2010 at 12:26:15PM +0200, Stefan Richter wrote: > Hi, > > I came across a report of the subject message. What does it mean; what > type of bug should be look for? > > https://bugzilla.redhat.com/show_bug.cgi?id=587178 > >>> > firewire_ohci 0000:04:00.4: PCI INT C -> GSI 16 (level, low) -> IRQ 16 > firewire_ohci 0000:04:00.4: setting latency timer to 64 > firewire_ohci: Added fw-ohci device 0000:04:00.4, OHCI version 1.0 > DRHD: handling fault status reg 2 > DMAR:[DMA Read] Request device [04:00.0] fault addr fffff000 > DMAR:[fault reason 02] Present bit in context entry is clear > DMAR:[DMA Read] Request device [04:00.0] fault addr fffff000 > DMAR:[fault reason 02] Present bit in context entry is clear > DMAR:[DMA Read] Request device [04:00.0] fault addr fffff000 > DMAR:[fault reason 02] Present bit in context entry is clear > <<< > > The log sounds as if this happens during from-device DMA of 04:00.4 into > a consistent buffer, yet the fault is logged for device 04:00.0. The > log is from a Dell M4500. The devices are, according to a web search, > 04:00.0 CardBus bridge [0607]: Ricoh Co Ltd Device [1180:e476] (rev 02) > 04:00.4 FireWire (IEEE 1394) [0c00]: Ricoh Co Ltd Device [1180:e832] > (rev 03) (prog-if 10) I would guess that the DMAR can't distinguish between the different devices behind the Cardbus bridge. Adding Dave Woodhouse. -- Matthew Wilcox Intel Open Source Technology Centre "Bill, look, we understand that you're interested in selling us this operating system, but compare it to ours. We can't possibly take such a retrograde step." -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |