Checking for Resource Conflicts
This section discusses techniques that can be used to detect resource conflicts.
The first technique involves dumping the arbiter data. The following example examines the arbiter data for the I/O ranges:
kd> !arbiter 1
DEVNODE ff0daf48
Port Arbiter "RootPort" at 8045b920
Allocated ranges:
10 - 1f S Owner ff0d6b30
22 - 3f S Owner ff0d6b30
44 - 47 S Owner ff0d6b30
4c - 6f S Owner ff0d6b30
72 - 7f S Owner ff0d6b30
90 - 91 S Owner ff0d6b30
93 - 9f S Owner ff0d6b30
a2 - bf S Owner ff0d6b30
d0 - ef S Owner ff0d6b30
100 - 2f7 S Owner ff0d6b30
300 - cf7 S Owner ff0d6b30
d00 - ffff S Owner ff0d6b30
Possible allocation:
< none >
DEVNODE ff0d2e28 (PCI_HAL\PNP0A03\0)
Port Arbiter "PCI I/O Port (b=00)" at e122c2c8
Allocated ranges:
0 - f Owner 00000000
20 - 21 Owner 00000000
40 - 43 Owner 00000000
48 - 4b Owner 00000000
60 - 60 Owner ff0d4030
64 - 64 Owner ff0d4030
70 - 71 Owner 00000000
80 - 8f Owner 00000000
92 - 92 Owner 00000000
a0 - a1 Owner 00000000
c0 - cf Owner 00000000
f0 - ff Owner 00000000
170 - 177 Owner ff0cf030
1ce - 1cf S Owner ff040040
2f8 - 2ff Owner 00000000
376 - 376 Owner ff0cf030
378 - 37f Owner ff0d4e70
3b0 - 3bb S Owner ff040040
3c0 - 3cf S Owner ff0bb900
3c0 - 3df S Owner ff040040
3d4 - 3db S Owner ff0bb900
3de - 3df S Owner ff0bb900
3ec - 3ef Owner ff0d0b50 (This device conflicts with another device, see below)
3f2 - 3f5 Owner ff0d4770
3f7 - 3f7 S Owner ff0d4770
3f8 - 3ff Owner ff0d4af0
778 - 77b Owner ff0d4e70
cf8 - cff Owner 00000000
1000 - 10ff Owner ff0d1030
1400 - 140f Owner ff0d1d30
1410 - 141f Owner ff0d1890
10000 - ffffffffffffffff Owner 00000000
Possible allocation:
< none >
Note that there are two arbiters: one located in the root of the device tree, and one in PCI_HAL. Also note that the PCI arbiter claims and preallocates ranges for the devices it arbitrates (0xD000-0xFFFF, which is later suballocated by the PCI arbiter for its devices). The Owner field indicates the device object that owns the range. A value of zero for Owner indicates that the range is not on the bus. In the case of a PCI bridge, for example, all the ranges it does not pass will be assigned to NULL.
In the following example, the PCI bridge passes I/O 0xD000-0xDFFFF so its arbiter will contain the following two ranges:
0-CFFFF Owner 00000000
E0000-FFFFFFFFFFFFFFFF Owner 00000000
The FFFFFFFFFFFFFFFF is because all arbitrated resources are treated as 64-bit ranges.
Examples:
kd> !devobj ff0bb900
Device object (ff0bb900) is for:
Video0 \Driver\mga_mil DriverObject ff0bbc10
Current Irp 00000000 RefCount 1 Type 00000023 Flags 0000204c
DevExt ff0bb9b8 DevNode ff0bb808
Device queue is not busy.
kd> !devnode ff0bb808
DevNode 0xff0bb808 for PDO 0xff0bb900 at level 0xffffffff
Parent 0xff0daf48 Sibling 0000000000 Child 0000000000
InterfaceType 0xffffffff Bus Number 0xffffffff
TargetDeviceNotify List - f 0xff0bb86c b 0xff0bb86c
Flags (0x00000400) DNF_RESOURCE_REPORTED
kd> !devnode ff0bb808 6
DevNode 0xff0bb808 for PDO 0xff0bb900 at level 0xffffffff
Parent 0xff0daf48 Sibling 0000000000 Child 0000000000
InterfaceType 0xffffffff Bus Number 0xffffffff
TargetDeviceNotify List - f 0xff0bb86c b 0xff0bb86c
Flags (0x00000400) DNF_RESOURCE_REPORTED
CmResourceList at 0xe12474e8 Version 0.0 Interface 0x5 Bus #0
Entry 0 - Port (0x1) Shared (0x3)
Flags (0x01) - PORT_MEMORY PORT_IO
Range starts at 0x3c0 for 0x10 bytes
Entry 1 - Port (0x1) Shared (0x3)
Flags (0x01) - PORT_MEMORY PORT_IO
Range starts at 0x3d4 for 0x8 bytes
Entry 2 - Port (0x1) Shared (0x3)
Flags (0x01) - PORT_MEMORY PORT_IO
Range starts at 0x3de for 0x2 bytes
Entry 3 - Memory (0x3) Device Exclusive (0x1)
Flags (0000) - READ_WRITE
Range starts at 0x0000000040000000 for 0x4000 bytes
Entry 4 - Memory (0x3) Device Exclusive (0x1)
Flags (0000) - READ_WRITE
Range starts at 0x0000000040800000 for 0x800000 bytes
As shown in the example, this operation retrieved the legacy video card that owns the range 3c0-3cf. The same device object is listed near the other ranges it owns (3de-3df and 3d4-3dc). Using the same tracking technique, the range of 3f8-3ff is determined to be that used by the serial port.
A similar technique is required to translate the interrupts:
kd> !arbiter 4
DEVNODE ff0daf48
Interrupt Arbiter "RootIRQ" at 8045bae0
Allocated ranges:
31 - 31 Owner ff0d4030
34 - 34 S Owner ff0d4af0
36 - 36 Owner ff0d4770
3b - 3b S Owner ff0d1030
3b - 3b S Owner ff0d1d30
3c - 3c Owner ff0d3c70
3f - 3f Owner ff0cf030
Possible allocation:
< none >
Note that there is a single arbiter for interrupts: the root arbiter.
For example, translate the interrupt 3F to an IRQ. First dump the device object, then the devnode:
kd> !devobj ff0cf030
Device object (ff0cf030) is for:
IdeFdoff0d0398Channel1 \Driver\IntelIde DriverObject ff0d0530
Current Irp 00000000 RefCount 0 Type 00000004 Flags 00001040AttachedDev ff0cd030
DevExt ff0cf0e8 DevNode ff0cfe88
Device queue is not busy.
kd> !devnode ff0cfe88 6
DevNode 0xff0cfe88 for PDO 0xff0cf030 at level 0x3
Parent 0xff0d1348 Sibling 0000000000 Child 0xff0c84a8
InterfaceType 0xffffffff Bus Number 0xfffffff0
InstancePath is "PCIIDE\IDEChannel\1&1"
ServiceName is "atapi"
TargetDeviceNotify List - f 0xff0cfeec b 0xff0cfeec
Flags (0x6000120b) DNF_PROCESSED, DNF_STARTED,
DNF_ENUMERATED, DNF_RESOURCE_ASSIGNED,
DNF_ADDED, DNF_HAS_BOOT_CONFIG
Unknown flags 0x40000000
CmResourceList at 0xe12321c8 Version 0.0 Interface 0x1 Bus #0
Entry 0 - Port (0x1) Device Exclusive (0x1)
Flags (0x01) - PORT_MEMORY PORT_IO
Range starts at 0x170 for 0x8 bytes
Entry 1 - Port (0x1) Device Exclusive (0x1)
Flags (0x01) - PORT_MEMORY PORT_IO
Range starts at 0x376 for 0x1 bytes
Entry 2 - Interrupt (0x2) Device Exclusive (0x1)
Flags (0x01) - LATCHED
Level 0xf, Vector 0xf, Affinity 0xffffffff
IoResList at 0xe12363c8 : Interface 0x1 Bus 0 Slot 0
Reserved Values = {0x0002e0d0, 0x00920092, 0xe1235508}
Alternative 0 (Version 1.1)
Preferred Descriptor 0 - NonArbitrated/ConfigData (0x80) Shared (0x3)
Flags (0000) -
Data: : 0x1 0x61004d 0x680063
Preferred Descriptor 1 - Port (0x1) Device Exclusive (0x1)
Flags (0x01) - PORT_IO
0x000008 byte range with alignment 0x000001
170 - 0x177
Preferred Descriptor 2 - Port (0x1) Device Exclusive (0x1)
Flags (0x01) - PORT_IO
0x000001 byte range with alignment 0x000001
376 - 0x376
Preferred Descriptor 3 - Interrupt (0x2) Device Exclusive (0x1)
Flags (0x01) - LATCHED
0xf - 0xf
Alternative 1 (Version 1.1)
Preferred Descriptor 0 - Port (0x1) Device Exclusive (0x1)
Flags (0x01) - PORT_IO
0x000008 byte range with alignment 0x000001
170 - 0x177
Preferred Descriptor 1 - Port (0x1) Device Exclusive (0x1)
Flags (0x01) - PORT_IO
0x000001 byte range with alignment 0x000001
376 - 0x376
Preferred Descriptor 2 - Interrupt (0x2) Device Exclusive (0x1)
Flags (0x01) - LATCHED
0xf - 0xf
For example, try to determine if there is a resource conflict that caused this device not to start, starting with a devnode:
kd> !devnode 0xff0d4bc8 6
DevNode 0xff0d4bc8 for PDO 0xff0d4cb0 at level 0
Parent 0xff0daf48 Sibling 0xff0d4a08 Child 0000000000
InterfaceType 0xffffffff Bus Number 0xffffffff
InstancePath is "Root\*PNP0501\1_0_17_2_0_0"
ServiceName is "Serial"
TargetDeviceNotify List - f 0xff0d4c2c b 0xff0d4c2c
Flags (0x60001129) DNF_PROCESSED, DNF_ENUMERATED,
DNF_MADEUP, DNF_INSUFFICIENT_RESOURCES,
DNF_ADDED, DNF_HAS_BOOT_CONFIG
Unknown flags 0x40000000
IoResList at 0xe1251e28 : Interface 0x1 Bus 0 Slot 0
Reserved Values = {0x0043005c, 0x006e006f, 0x00720074}
Alternative 0 (Version 1.1)
Preferred Descriptor 0 - NonArbitrated/ConfigData (0x80) Undetermined Shar
ing (0)
Flags (0000) -
Data: : 0xc000 0x0 0x0
Preferred Descriptor 1 - Port (0x1) Undetermined Sharing (0)
Flags (0x05) - PORT_IO 10_BIT_DECODE
0x000008 byte range with alignment 0x000001
3e8 - 0x3ef
Preferred Descriptor 2 - Interrupt (0x2) Shared (0x3)
Flags (0x01) - LATCHED
0x5 - 0x5
Alternative 1 (Version 1.1)
Preferred Descriptor 0 - NonArbitrated/ConfigData (0x80) Undetermined Shar
ing (0)
Flags (0000) -
Data: : 0xc000 0x0 0x0
Preferred Descriptor 1 - Port (0x1) Undetermined Sharing (0)
Flags (0x05) - PORT_IO 10_BIT_DECODE
0x000008 byte range with alignment 0x000008
3e8 - 0x3ef
Preferred Descriptor 2 - Interrupt (0x2) Shared (0x3)
Flags (0x01) - LATCHED
0x5 - 0x5
First, make the assumption that this is an I/O conflict and dump the arbiters (see the preceding example). The result shows that the range 0x3EC-0x3EF is owned by 0xFF0D0B50, which overlaps the serial device's resources request. Next, dump the device object for the owner of this range, and then dump the devnode for the owner:
kd> !devobj ff0d0b50
Device object (ff0d0b50) is for:
Resource00413e \Driver\isapnp DriverObject ff0d0e10
Current Irp 00000000 RefCount 0 Type 00000004 Flags 00001040
DevExt ff0d0c08 DevNode ff0d0a68
Device queue is not busy.
kd> !devnode ff0d0a68 6
DevNode 0xff0d0a68 for PDO 0xff0d0b50 at level 0xffffffff
Parent 0xff0daf48 Sibling 0000000000 Child 0000000000
InterfaceType 0xffffffff Bus Number 0xffffffff
Duplicate PDO 0xff0d0e10 TargetDeviceNotify List - f 0xff0d0acc b 0xff0d0acc
Flags (0x00000421) DNF_PROCESSED, DNF_MADEUP,
DNF_RESOURCE_REPORTED
CmResourceList at 0xe1233628 Version 0.0 Interface 0x1 Bus #0
Entry 0 - Port (0x1) Device Exclusive (0x1)
Flags (0x01) - PORT_MEMORY PORT_IO
Range starts at 0x3ec for 0x4 bytes
This is a "pseudo-devnode" that corresponds to the range allocated by the ISAPNP driver for its read data port.
To determine the resources that the PnP Manager assigned to a particular device when it attempted to start the device:
Place a breakpoint on the routine that is called when the IRP_MN_START_DEVICE request is received by the driver. You can also place a breakpoint on the driver's dispatch routine (if you know its name). In both cases, the driver and its symbols should be loaded. This may require you to set an initial breakpoint.
For example, for PCMCIA you can set a breakpoint on pcmcia!pcmciastartpccard. The advantage of using this particular routine is that its second parameter is a CM Resource List that you can dump using !cmreslist (eliminating step 3). See the following PCMCIA example.
When you have determined which device is of interest, dump the device object (if you have not done so already), and then dump the devnode with the CM Resource List. Check which resources were assigned to the device. You may also check whether the resources are a subset of the I/O Resource List. Then type g or single step through the procedure, and determine whether the device was started and which resources were assigned. If a device was offered a set of resources to start but failed to do so, the driver might not be behaving properly (for example, if it incorrectly declared that it can use a set of resources it cannot actually use).
Example:
ntoskrnl!IopStartDevice:
80420212 55 push ebp
kd> kb
ChildEBP RetAddr Args to Child
f64138c0 8048b640 ff0ce870 ff0d7c08 ff0cde88 ntoskrnl!IopStartDevice (!devobj ff0ce870)
f64138f0 8048d8e7 ff0cde88 f6413978 ff0cddc8 ntoskrnl!IopStartAndEnumerateDevice
+0x1a
f6413900 8048de7f ff0cde88 f6413978 ff0cf448 ntoskrnl!IopProcessStartDevicesWork
er+0x43
f6413910 8048d8d5 ff0cf448 8048d8a4 f6413978 ntoskrnl!IopForAllChildDeviceNodes+
0x1f
f6413924 8048de7f ff0cf448 f6413978 ff0d3f48 ntoskrnl!IopProcessStartDevicesWork
er+0x31
f6413934 8048d8d5 ff0d3f48 8048d8a4 f6413978 ntoskrnl!IopForAllChildDeviceNodes+
0x1f
f6413948 8048d893 ff0d3f48 f6413978 e12052e8 ntoskrnl!IopProcessStartDevicesWork
er+0x31
f641395c 804f6f1b ff0d7c08 f6413978 8045c520 ntoskrnl!IopProcessStartDevices+0x1
f
f64139d0 804f5cc1 80088000 f6413aec 8045bba0 ntoskrnl!IopInitializeBootDrivers+0
x2f9
f6413b24 804f4db3 80088000 00000001 00000000 ntoskrnl!IoInitSystem+0x3a6
f6413da8 80447610 80088000 00000000 00000000 ntoskrnl!Phase1Initialization+0x6a3
f6413ddc 8045375a 804f4710 80088000 00000000 ntoskrnl!PspSystemThreadStartup+0x5
4
00000000 00000000 00000000 00000000 00000000 ntoskrnl!KiThreadStartup+0x16
kd> !devobj ff0ce870
Device object (ff0ce870) is for:
NTPNP_PCI0002 \Driver\PCI DriverObject ff0ceef0
Current Irp 00000000 RefCount 0 Type 00000022 Flags 00001040AttachedDev ff0cb9e0
DevExt ff0ce928 DevNode ff0cde88
Device queue is not busy.
kd> !devnode ff0cde88 6
DevNode 0xff0cde88 for PDO 0xff0ce870 at level 0x2
Parent 0xff0cf448 Sibling 0xff0cddc8 Child 0000000000
InterfaceType 0xffffffff Bus Number 0xffffffff
InstancePath is "PCI\VEN_8086&DEV_7010\0&69"
ServiceName is "intelide"
TargetDeviceNotify List - f 0xff0cdeec b 0xff0cdeec
Flags (0x00001209) DNF_PROCESSED, DNF_ENUMERATED,
DNF_RESOURCE_ASSIGNED, DNF_ADDED
(note that the device is not yet started)
CmResourceList at 0xe120fce8 Version 0.0 Interface 0x5 Bus #0
Entry 0 - Port (0x1) Device Exclusive (0x1)
Flags (0x01) - PORT_MEMORY PORT_IO
Range starts at 0xfff0 for 0x10 bytes (these are the resources used: 0xfff0-0xffff)
Entry 1 - DevicePrivate (0x81) Device Exclusive (0x1)
Flags (0000) -
Data - {0x00000001, 0x00000004, 0000000000}
IoResList at 0xe120df88 : Interface 0x5 Bus 0 Slot 0x2d
Alternative 0 (Version 1.1)
Descriptor 0 - Port (0x1) Device Exclusive (0x1)
Flags (0x01) - PORT_IO
0x000010 byte range with alignment 0x000010
0 - 0xffff (it could have used any 16 bytes that are 16-byte aligned between 0 and 0xffff)
Descriptor 1 - DevicePrivate (0x81) Device Exclusive (0x1)
Flags (0000) -
Data: : 0x1 0x4 0x0
Example for PCMCIA:
kd> bp pcmcia!pcmciastartpccard
Loading symbols for 0x8039d000 pcmcia.sys -> pcmcia.sys
kd> kb
Loading symbols for 0x80241000 ndis.sys -> ndis.sys
ChildEBP RetAddr Args to Child
f6413814 803a7cbd ff0d0c30 e11d8808 ff0d0c30 pcmcia!PcmciaStartPcCard
f6413838 803a3798 ff0d0c30 ff0d1500 ff0d1588 pcmcia!PcmciaPdoPnpDispatch+0x169
f6413848 80418641 ff0d0c30 ff0d1588 00000000 pcmcia!PcmciaDispatch+0x3a
f641385c 802455cf ff0d1614 ff0d1638 00040000 ntoskrnl!IofCallDriver+0x35
f641387c 802497cf ff0d1588 ff0d0c30 ff0c8210 NDIS!ndisPassIrpDownTheStack+0x3b
f64138ac 80418641 ff0c8210 ff0d161c ff0d1640 NDIS!ndisPnPDispatch+0x1f9
f64138c0 8048de68 ff0c3508 ff0d16a8 00000000 ntoskrnl!IofCallDriver+0x35
f64138d4 8041ff5e ff0c8210 f64138f8 ff0c3508 ntoskrnl!IopAsynchronousCall+0x90
f6413920 8048b4ae ff0d0c30 ff0e0a68 ff0d16a8 ntoskrnl!IopStartDevice+0x76
f6413950 8048d707 ff0d16a8 f64139fc 00000000 ntoskrnl!IopStartAndEnumerateDevice+0x1a
f6413960 8048dc9f ff0d16a8 f64139fc ff0d1e88 ntoskrnl!IopProcessStartDevicesWorker+0x43
f6413970 8048d6f5 ff0d1e88 8048d6c4 f64139fc ntoskrnl!IopForAllChildDeviceNodes+0x1f
f6413984 8048dc9f ff0d1e88 f64139fc ff0d3268 ntoskrnl!IopProcessStartDevicesWorker+0x31
f6413994 8048d6f5 ff0d3268 8048d6c4 f64139fc ntoskrnl!IopForAllChildDeviceNodes+0x1f
f64139a8 8048dc9f ff0d3268 f64139fc ff0d7b28 ntoskrnl!IopProcessStartDevicesWorker+0x31
f64139b8 8048d6f5 ff0d7b28 8048d6c4 f64139fc ntoskrnl!IopForAllChildDeviceNodes+0x1f
f64139cc 8048d6b3 ff0d7b28 f64139fc 80087000 ntoskrnl!IopProcessStartDevicesWorker+0x31
f64139e0 804f6c97 ff0e0a68 f64139fc 8045c140 ntoskrnl!IopProcessStartDevices+0x1f
f6413a30 804f5601 000001e0 80087000 00000000 ntoskrnl!IopInitializeSystemDrivers+0x5b
f6413b7c 804f4820 80087000 00000001 00000000 ntoskrnl!IoInitSystem+0x3fe
kd> !cmreslist e11d8808
CmResourceList at 0xe11d8808 Version 0.0 Interface 0x1 Bus #0
Entry 0 - Interrupt (0x2) Device Exclusive (0x1)
Flags (0x01) - LATCHED
Level 0x9, Vector 0x9, Affinity 0xffffffff
Entry 1 - Port (0x1) Device Exclusive (0x1)
Flags (0x01) - PORT_MEMORY PORT_IO
Range starts at 0xdfe0 for 0x20 bytes (started with IRQ 9, IO dfe0-dfff)
Entry 2 - DevicePrivate (0x81) Device Exclusive (0x1)
Flags (0000) -
Data - {0x00010120, 0000000000, 0000000000}
kd> g
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