A USB device takes a long time to resume from "selective suspend" mode on a Windows Vista-based computer that uses UHCI USB controllers

On a Windows Vista-based computer that uses Universal Host Controller Interface (UHCI) USB controllers, a USB device takes a long time to resume from "selective suspend" mode. Usually, the USB device takes 500 to 1,200 milliseconds (ms) to resume from this mode.

Therefore, USB devices that are attached to the UHCI USB controller may take a long time to respond. For example, assume that you are using a fingerprint reader to capture user fingerprints. The fingerprint reader is attached to the UHCI USB controller on a Windows Vista-based computer. If the fingerprint reader is in "selective suspend" mode, the system may not capture the fingerprint after you swipe a finger on the receiver of the fingerprint reader. This behavior occurs because the fingerprint reader takes a long time to resume from "selective suspend" mode. You must swipe your finger again for the fingerprint reader to capture the fingerprint.

Note Typically, it takes about 20 ms to resume from "selective suspend" mode when you use either of the following configurations:

• Microsoft Windows XP-based computers that use UHCI USB controllers
• Windows Vista-based computers that use Open Host Controller Interface (OCHI) USB controllers

This problem occurs because Windows Vista has introduced a design change for the USB driver.

Windows Vista lets individual ports switch to "selective suspend" mode. However, the resume notification of a USB device that uses an UHCI controller does not trigger an interrupt unless the host controller is in "global suspend" mode. The resume notification is detected only when the rollover transfer descriptor (TD) is completed. The rollover TD is completed every 1,024 ms. Therefore, the USB device usually experiences a delay of 700 to 800 ms.

Service pack information

To resolve this problem, obtain the latest service pack for Windows Vista. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

Hotfix information

A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.

If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, contact Microsoft Customer Service and Support to obtain the hotfix.

Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft Web site: Note The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.

Prerequisites

No prerequisites are required.

Restart requirement

You must restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace any other hotfixes.

File information

The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time item in Control Panel.

Windows Vista, 32-bit versions

Windows Vista, 64-bit versions

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section. This problem was first corrected in Windows Vista Service Pack 1.

To determine th type of USB controller that the computer is using, follow these steps:

1. Click Start, type devmgmt.msc in the Start Search box, and then press ENTER.
2. Expand Universal Serial Bus controllers, and then determine the type of USB controller that the computer is using.

For more information about "selective suspend" mode, visit the following Microsoft Web site: For more information, click the following article number to view the article in the Microsoft Knowledge Base: