kdump regression related to usb3 hub update

[CAI Qian]

Hello Sarah and others,

There is a regression using the latest Sarah's xhci hubs-v3-rebase tree, kdump kernel reset itself (log at the end of email). The first kernel also setup using IOMMU (intel_iommu=on). Removed intel_iommu=on from the kdump kernel parameter alone did not solve the problem. This is only reproducible when the first kernel is using IOMMU.

My environment setup is:

PCI-E card -> USB3 Disk
           -> USB3 Hub -> USB3 Disk
                       -> USB2 Hub -> USB2 Disk

I have been identified one or a few of the following patches caused the problem but need more time to narrow it down.

288ead45fa6637e959015d055304f521cbbc0575
USB: remove bogus USB_PORT_FEAT_*_SPEED symbols

0eadcc09203349b11ca477ec367079b23d32ab91
usb: USB3.0 ch11 definitions

b1a72b70bbb82237b1041c78edee305503f6da31
USB: Remove bitmap #define from hcd.h

50e6c947c6340f7ba81deca99e8a37f458a00e49
USB: Fix usb_add_hcd() checkpatch errors.

0abde136582234dd720270ec3d5aeba69eae4d03
xhci: Rework port suspend structures for limited ports.

8c0d6f920004f065c2571f32b7c28e7f850e9810
xhci: Rename variables and reduce register reads.

ba764f4b37e2bcce069f6c9d96b8374ee85257ed
USB 3.0 Hub Changes

Loading usb-storage.ko module
Initializing USB Mass Storage driver...
usbcore: registered new interface driver usb-storage
USB Mass Storage support registered.
Waiting 8 seconds for driver initialization.
usb 7-1: New USB device found, idVendor=046d, idProduct=08af
usb 7-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0
usb 7-2: new low speed USB device number 3 using uhci_hcd
usb 7-2: New USB device found, idVendor=0624, idProduct=0307
usb 7-2: New USB device strings: Mfr=1, Product=2, SerialNumber=0
usb 7-2: Product: Avocent DSRIQ-USB
usb 7-2: Manufacturer: Avocent
input: Avocent Avocent DSRIQ-USB as /devices/pci0000:00/0000:00:1d.2/usb7/7-2/7-2:1.0/input/input1
generic-usb 0003:0624:0307.0001: input,hidraw0: USB HID v1.10 Keyboard [Avocent Avocent DSRIQ-USB] on usb-0000:00:1d.2-2/input0
input: Avocent Avocent DSRIQ-USB as /devices/pci0000:00/0000:00:1d.2/usb7/7-2/7-2:1.1/input/input2
generic-usb 0003:0624:0307.0002: input,hidraw1: USB HID v1.10 Mouse [Avocent Avocent DSRIQ-USB] on usb-0000:00:1d.2-2/input1
DRHD: handling fault status reg 602
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 702
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 2
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 102
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 202
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 302
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 402
DMAR:[DMA Write] Request device [0b:00.0] fault addr ffbfb000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 502
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 602
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 702
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 2
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 102
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 202
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 302
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 402
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 502
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 602
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
Loading mii.ko module
Loading v4l2-compat-ioctl32.ko module
Loading mmicrocode: CPU0 sig=0x206c2, pf=0x1, revision=0xc
icrocode.ko module
DRHD: handling fault status reg 702
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 2
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 102
DMAR:[DMA Write] Request device [0b:00.0] fault addr ffbfa000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 202
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 302
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 402
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 502
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 602
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 702
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 2
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 102
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 202
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 302
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 402
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 502
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 602
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 702
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 2
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 102
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 202
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 302
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 402
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 502
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 602
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 702
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 2
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 102
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 202
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 302
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 402
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 502
DMAR:[DMA Write] Request device [0b:00.0] fault addr ffbf9000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 602
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 702
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 2
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 102
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 202
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 302
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 402
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 502
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 602
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 702
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 2
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 102
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 202
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 302
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 402
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 502
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 602
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 702
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 2
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 102
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 202
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 302
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 402
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 502
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 602
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 702
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 2
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 102
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 202
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 302
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 402
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 502
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 602
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 702
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 2
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 102
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 202
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 302
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 402
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 502
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 602
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 702
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 2
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 102
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 202
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 302
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 402
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 502
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 602
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 702
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 2
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 102
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 202
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 302
DMAR:[DMA Write] Request device [0b:00.0] fault addr ffbf8000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 402
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 502
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 602
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 702
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 2
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 102
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 202
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 302
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 402
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 502
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 602
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 702
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 2
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 102
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 202
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 302
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 402
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 502
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 602
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 702
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 2
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 102
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 202
DMAR:[DMA Write] Request device [0b:00.1] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
DRHD: handling fault status reg 302
DMAR:[DMA Write] Request device [0b:00.0] fault addr fffff000 
DMAR:[fault reason 01] Present bit in root entry is clear
<reset>
Initializing cgroup subsys cpuset
Linux version 2.6.38-rc5+ ....

Thanks.

CAI Qian