PRB: Using Linked URBs in a WDM Driver Causes Page-Faults (190527)



The information in this article applies to:

  • Microsoft Win32 Device Driver Kit (DDK) Windows 98

This article was previously published under Q190527

SYMPTOMS

The USB Request Block (URB) structure, which a WDM driver uses to submit a request to a USB device, defines an "UrbLink" element that is intended to allow the driver to submit a linked list of URBs to the WDM USB driver stack. When you use this field with the WDM USB driver stacks shipped in Windows 98, Windows 95 OSR 2.1, and Windows 95 OSR 2.5, a system failure such as page-fault to typically occurs.

CAUSE

The WDM USB driver stacks shipped in Windows 98, Windows 95 OSR 2.1, and Windows 95 OSR 2.5 do not provide any support for linked URBs.

RESOLUTION

A WDM driver must never submit linked URBs to the WDM USB driver stack when running under Windows 98, Windows 95 OSR 2.1, or Windows 95 OSR 2.5. The UrbLink element of the URB must always be NULL.

STATUS

This behavior is by design.

Modification Type:MinorLast Reviewed:7/22/2004
Keywords:kbprb KB190527