USB enumeration doesn work after first round

[deepaknaik26]

USB enumeration

USB enumeration successfully compleates in some of the PC ,, but not in all.

In the first round up to configuration descriptor it works well. After that host request for qualifier descriptor.

After that it will just not works. The same thing will work perfectly in some of the host.

Where may be the problem .. To solve this what I have to see. The platform is same even though I am getting this problem ..


Please give ur valuable suggesion.

 

[vivek]

Re: USB enumeration

make sure whether ur USB device is responding to the get qualifier descriptor request. Ur device may be working in hosts which may not request for the device qualifier request. If ur device is not responding with the qualifier descriptor enumeration will not happen. qualifier descritpor is very similar to device descriptor