As I remember I write a file on 2013-07-24named “Attention in USB client driver attach function”, here is one sister forthat one.


Following more test was done, we foundanother issue, what we can do in the attach function only to parse thedescriptors of the lpInterface a parameter transferred from USB stack, and onlyreturn if the driver support this interface or not.


May be you can do more operation in theattach function when the device is a single object, but please do not do thatfor a composit one. We must make sure the attach function spend less time,because there is some special case, such as plug/unplug in a high speed. Thiswill make problem, we are doing the attach function, but device was unpluged.


Conclusion:

Do not implement the function call haverelation with transfer, because it will speed much time even if it will neverreturn in some special case.