BUG: WinNT X86 MPS HAL Can Fail To Map System Relative IRQs

• Microsoft Windows NT 4.0 on the following platform:

  - x86

SYMPTOMS

Under very specific circumstances, Windows NT might fail to assign a system- relative Interrupt Request Level (IRQL) to a Peripheral Component Interconnect (PCI) device.

A driver first calls HalAssignSlotResources to retrieve the bus-relative IRQL for the PCI device. When the driver calls HalGetInterruptVector to map the bus-relative IRQL, the call might fail.

CAUSE

This problem is caused when a multiprocessor hardware-abstraction layer (HAL) is used on a specific PCI configuration. For any non-zero bus, if a PCI device is at Device #0 and it is the only PCI device on that bus, the interrupt assignment fails. If there is more than one PCI device on the bus, this problem does not occur.

This problem has occurred on systems with PCI Accelerated Graphics Port (AGP) video devices because they are typically the only devices on the bus and they are not on bus zero. Also, systems with multiple PCI buses might have this problem.

STATUS

Microsoft has confirmed this to be a problem in Windows NT version 4.0.

Hardware developers writing device drivers under multiple PCI bus systems might experience this problem. If your PCI device drivers are configured as described above and you experience this failure when calling HalGetInterruptVector, contact Microsoft Technical Support to obtain a hotfix.

A supported hotfix is now available, but has not been fully regression tested and should be applied only to systems that have this specific problem. Unless you are severely affected by this problem, Microsoft recommends that you wait for the next Service Pack that contains this fix. Contact Microsoft Technical Support for more information.

Version           : WINNT:4.0
Platform          : winnt
Hardware          : x86
Issue type        : kbbug
Solution Type     : kbpending