Symptoms

On a computer that is running Windows 7 or Windows Server 2008 R2, you attach a device that uses the IEEE 1394 bus to transfer data. The device uses a driver that is controlled by the Windows 7 1394 OHCI Host Controller driver. When you start Isochronous transfer from the device to the computer, data transfer may not successfully finish.Note This problem may occur if the driver for the IEEE 1394 device only attaches enough Isochronous buffers for a single frame of data, and the device driver detaches and reattaches this buffer in between each frame.

Cause

This problem occurs only when the Isochronous transfer runs to the end of the last buffer that is attached to the Isochronous transfer context, and that buffer is detached from the Isochronous transfer context before additional buffers are attached. This problem may occur because the Windows 7 1394 OHCI Host Controller driver does not correctly clean up an Isochronous transfer context when the last buffer is processed and detached from the Isochronous transfer context. When additional buffers are attached to the Isochronous context, and the Isochronous transfer is restarted, the last buffer in the previous transfer is processed again, instead of starting with the first buffer in the new transfer.

Resolution

Hotfix information

A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that described in this article. Apply this hotfix only to systems that are experiencing the problem described in this article. 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 website:

http://support.microsoft.com/contactus/?ws=supportNote 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

To apply this hotfix, you must be running one of the following operating systems:

  • Windows 7

  • Windows 7 Service Pack 1 (SP1)

  • Windows Server 2008 R2

  • Windows Server 2008 R2 Service Pack 1 (SP1)

Registry information

To use the hotfix in this package, you do not have to make any changes to the registry.

Restart information

You may have to restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace a previously released hotfix.

File information

The global version of this hotfix installs files that have the attributes that are listed in the following tables. The dates and the times for these files are listed in Coordinated Universal Time (UTC). The dates and the times for these files on your local computer are displayed in your local time together with your current daylight saving time (DST) bias. Additionally, the dates and the times may change when you perform certain operations on the files.

Windows 7 and Windows Server 2008 R2 file information notes

Important Windows 7 hotfixes and Windows Server 2008 R2 hotfixes are included in the same packages. However, hotfixes on the Hotfix Request page are listed under both operating systems. To request the hotfix package that applies to one or both operating systems, select the hotfix that is listed under "Windows 7/Windows Server 2008 R2" on the page. Always refer to the "Applies To" section in articles to determine the actual operating system that each hotfix applies to.

  • The files that apply to a specific product, SR_Level (RTM, SPn), and service branch (LDR, GDR) can be identified by examining the file version numbers as shown in the following table.

    Version

    Product

    SR_Level

    Service branch

    6.1.760  0. 20xxx

    Windows 7 and Windows Server 2008 R2

    RTM

    LDR

    6.1.760  1. 21xxx

    Windows 7 and Windows Server 2008 R2

    SP1

    LDR

  • The MANIFEST files (.manifest) and the MUM files (.mum) that are installed for each environment are listed separately in the "Additional file information for Windows Server 2008 R2 and for Windows 7" section. MUM and MANIFEST files, and the associated security catalog (.cat) files, are extremely important to maintain the state of the updated components. The security catalog files, for which the attributes are not listed, are signed with a Microsoft digital signature.

For all supported x86-based versions of Windows 7

File name

File version

File size

Date

Time

Platform

1394ohci.sys

6.1.7600.20861

164,864

18-Dec-2010

03:58

x86

1394ohci.sys

6.1.7601.21624

164,864

18-Dec-2010

06:29

x86

For all supported x64-based versions of Windows 7 and of Windows Server 2008 R2

File name

File version

File size

Date

Time

Platform

1394ohci.sys

6.1.7600.20861

230,400

18-Dec-2010

04:22

x64

1394ohci.sys

6.1.7601.21624

229,888

18-Dec-2010

07:05

x64

For all supported IA-64-based versions of Windows Server 2008 R2

File name

File version

File size

Date

Time

Platform

1394ohci.sys

6.1.7600.20861

514,560

18-Dec-2010

03:49

IA-64

1394ohci.sys

6.1.7601.21624

515,584

18-Dec-2010

08:01

IA-64

Workaround

To work around this problem, change the behavior of the IEEE 1394 device driver to provide sufficient buffers so that the Isochronous transfer never runs to the end of the last buffer. This would be a typical implementation to provide continuous streaming of Isochronous data.

Status

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

More Information

This problem occurs if the IEEE 1394 device driver implements the following sequence of operations:

  1. Set up the Isochronous transfer. This includes allocating resources and attaching buffers.For more information about how to set up the Isochronous transfer, visit the following Microsoft Developer Network (MSDN) websites:

    Setting Up Isochronous Transfer for IEEE 1394 Devices REQUEST_GET_SPEED_BETWEEN_DEVICES REQUEST_ISOCH_ALLOCATE_BANDWIDTH REQUEST_ISOCH_ALLOCATE_CHANNEL REQUEST_ISOCH_ALLOCATE_RESOURCES REQUEST_ISOCH_ATTACH_BUFFERS

  2. Start the Isochronous Listen or Talk transfer [transfer #1].For more information about how to start the Isochronous Listen or Talk transfer, visit the following Microsoft Developer Network (MSDN) websites:

    REQUEST_ISOCH_LISTEN REQUEST_ISOCH_TALK

  3. Isochronous data is transferred.

  4. IEEE 1394 device driver's Isochronous callback routine is invoked.For more information about how to invoke the Isochronous callback routine, visit the following Microsoft Developer Network (MSDN) website:

    ISOCH_DESCRIPTOR

  5. Stop the Isochronous transfer.For more information about how to stop the Isochronous transfer, visit the following Microsoft Developer Network (MSDN) website:

    REQUEST_ISOCH_STOP

  6. Detach buffers.For more information about how to detach the buffers, visit the following Microsoft Developer Network (MSDN) website:

    REQUEST_ISOCH_DETACH_BUFFERS

  7. Process buffer data.

    • For Isochronous Listen operations, the IEEE 1394 device driver would process the data that is received in the Isochronous buffers.

    • For Isochronous Talk operations, the IEEE 1394 device driver would prepare the Isochronous buffers with the data to be transmitted.

  8. Attach buffers.For more information about how to attach the buffers, visit the following Microsoft Developer Network (MSDN) website:

    REQUEST_ISOCH_ATTACH_BUFFERS

  9. Start the Isochronous Listen or Talk transfer [transfer #2].For more information about how to start the Isochronous Listen or Talk transfer, visit the following Microsoft Developer Network (MSDN) websites:

    REQUEST_ISOCH_LISTEN REQUEST_ISOCH_TALK

In this sequence of operations, when the second Isochronous Listen is started, the value written to the host controller's Command Pointer register is set to point to the LAST Command Descriptor from the PREVIOUS (completed) Isochronous transfer, instead of to the FIRST Command Descriptor in the NEW Isochronous transfer.This problem does not occur if the IEEE 1394 device driver implements the following sequence of operations:

  1. Set up the Isochronous transfer. This includes allocating resources and attaching buffers.For more information about how to set up the Isochronous transfer, visit the following Microsoft Developer Network (MSDN) websites:

    Setting Up Isochronous Transfer for IEEE 1394 Devices REQUEST_GET_SPEED_BETWEEN_DEVICES REQUEST_ISOCH_ALLOCATE_BANDWIDTH REQUEST_ISOCH_ALLOCATE_CHANNEL REQUEST_ISOCH_ALLOCATE_RESOURCES REQUEST_ISOCH_ATTACH_BUFFERSNote Make sure that you attach sufficient buffers so that additional buffers remain attached after the transfer of the current frame is complete, and the Isochronous callback routine in the corresponding Isochronous descriptor is invoked.

  2. Start the Isochronous Listen or Talk transfer [transfer #1].For more information about how to start the Isochronous Listen or Talk transfer, visit the following Microsoft Developer Network (MSDN) websites:

    REQUEST_ISOCH_LISTEN REQUEST_ISOCH_TALK

  3. Isochronous data is transferred.

  4. IEEE 1394 device driver's Isochronous callback routine is invoked.For more information about how to invoke the Isochronous callback routine, visit the following Microsoft Developer Network (MSDN) website:

    ISOCH_DESCRIPTOR

  5. Detach buffers.For more information about how to detach the buffers, visit the following Microsoft Developer Network (MSDN) website:

    REQUEST_ISOCH_DETACH_BUFFERS

  6. Process buffer data.

    • For Isochronous Listen operations, the IEEE 1394 device driver would process the data that is received in the Isochronous buffers.

    • For Isochronous Talk operations, the IEEE 1394 device driver would prepare the Isochronous buffers with the data to be transmitted.

  7. Attach buffers.For more information about how to attach the buffers, visit the following Microsoft Developer Network (MSDN) website:

    REQUEST_ISOCH_ATTACH_BUFFERS

  8. Repeat steps 4 through 7 to continue transferring Isochronous data continuously.

  9. Stop the Isochronous transfer.For more information about how to stop the Isochronous transfer, visit the following Microsoft Developer Network (MSDN) website:

    REQUEST_ISOCH_STOP

For more information about how anIEEE 1394 device driver performs Isochronous transfers, visit the following Microsoft Developer Network (MSDN) websites:

Setting Up Isochronous Transfer for IEEE 1394 Devices Buffering Isochronous DMA Transfers for IEEE 1394 Devices For a description of a typical sequence for performing Isochronous data transfers to or from an IEEE 1394 device, click the following article number to view the article in the Microsoft Knowledge Base:

970076 An isochronous data transfer through an IEEE 1394 device suddenly stops in Windows Vista or in Windows Server 2008For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:

824684 Description of the standard terminology that is used to describe Microsoft software updates

Additional file information for Windows 7 and for Windows Server 2008 R2

Additional files for all supported x86-based versions of Windows 7

File name

Update.mum

File version

Not applicable

File size

2,331

Date (UTC)

20-Dec-2010

Time (UTC)

21:50

Platform

Not applicable

File name

X86_1394.inf_31bf3856ad364e35_6.1.7600.20861_none_fba0efd5804c7eab.manifest

File version

Not applicable

File size

3,572

Date (UTC)

20-Dec-2010

Time (UTC)

21:52

Platform

Not applicable

File name

X86_1394.inf_31bf3856ad364e35_6.1.7601.21624_none_fdb58d697d4fc6d8.manifest

File version

Not applicable

File size

3,572

Date (UTC)

20-Dec-2010

Time (UTC)

21:52

Platform

Not applicable

Additional files for all supported x64-based versions of Windows 7 and of Windows Server 2008 R2

File name

Amd64_1394.inf_31bf3856ad364e35_6.1.7600.20861_none_57bf8b5938a9efe1.manifest

File version

Not applicable

File size

3,576

Date (UTC)

20-Dec-2010

Time (UTC)

21:55

Platform

Not applicable

File name

Amd64_1394.inf_31bf3856ad364e35_6.1.7601.21624_none_59d428ed35ad380e.manifest

File version

Not applicable

File size

3,576

Date (UTC)

20-Dec-2010

Time (UTC)

21:55

Platform

Not applicable

File name

Update.mum

File version

Not applicable

File size

2,347

Date (UTC)

20-Dec-2010

Time (UTC)

21:50

Platform

Not applicable

Additional files for all supported IA-64-based versions of Windows Server 2008 R2

File name

Ia64_1394.inf_31bf3856ad364e35_6.1.7600.20861_none_fba293cb804a87a7.manifest

File version

Not applicable

File size

3,574

Date (UTC)

20-Dec-2010

Time (UTC)

21:50

Platform

Not applicable

File name

Ia64_1394.inf_31bf3856ad364e35_6.1.7601.21624_none_fdb7315f7d4dcfd4.manifest

File version

Not applicable

File size

3,574

Date (UTC)

20-Dec-2010

Time (UTC)

21:50

Platform

Not applicable

File name

Update.mum

File version

Not applicable

File size

1,933

Date (UTC)

20-Dec-2010

Time (UTC)

21:50

Platform

Not applicable

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