An Audio Streaming Input and Output (ASIO) driver may not work correctly on a Windows Vista-based computer

On a Windows Vista-based computer, an Audio Streaming Input and Output (ASIO) driver may not work correctly. When this problem occurs, you experience the following symptoms.

Symptom 1

When the ASIO driver calls the GetLinkPositionRegister routine that is provided in the Microsoft high-definition audio device driver interface (DDI), the GetLinkPositionRegister routine always returns 0 for the current direct memory access (DMA) position. In this situation, the ASIO driver may be unable to initialize. This symptom occurs only when certain hardware audio chipsets are installed. For example, this symptom occurs on a computer that has the ATI SB460 Southbridge chipset installed.

Symptom 2

An application can use the AUDCLNT_STREAMFLAGS_EVENTCALLBACK flag to open an exclusive-mode audio stream in pull mode. In this situation, the audio engine should signal an event that is provided by the application to indicate that the audio buffer is ready for processing. However, the audio engine does not correctly signal the event on a Windows Vista-based computer.

Service Pack Information

This problem is corrected in Windows Vista Service Pack 1. 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 Microsoft Windows Vista Service Pack 1.

For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:
The third-party products that this article discusses are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, about the performance or reliability of these products.