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  2. Device description in Device Manager changes in the AMD Carrizo system after you disable or enable an xHCI controller

Device description in Device Manager changes in the AMD Carrizo system after you disable or enable an xHCI controller

Symptoms

When this issue occurs, the device description in Device Manager changes from AMD USB 3.0 eXtensible Host Controller to Standard USB 3.0 eXtensible Host Controller in the AMD Carrizo connected standby system. The device description does not change back until you restart the computer.

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Cause

When you disable the device in AMD Carrizo system, the xHCI controller goes into a D3cold state. The power rail of the device is disconnected. However, the Pci.sys driver thinks the device is still in a D0 state and does not know that the device is actually in a D3cold state. 

When you enable the device during the xHCI initialization, the pci.sys driver is trying to read the config space of xHCI controller to obtain the description data. 

However, because the power of the device is not up, the pci.sys driver can only read 0xFFFF for the vendor ID that maps to Standard. After the pci.sys driver sets up the description data, the system creates the device object, brings the device back to the D0 state, and the power of the device is up again.

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Resolution

There is no functionality loss for this issue.


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More Information

Third-party information disclaimer
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.

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Keywords: kbsurveynew, kbexpertiseadvanced, kbprb, kbtshoot, kb

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Article Info
Article ID : 3037080
Revision : 1
Created on : 1/7/2017
Published on : 2/16/2015
Exists online : False
Views : 78