As you may notice it already, when a USB flash drive is attached into usb host, a drive letter window pops up after this device gets enumerated.
Now I face a problem when I tested a USB3 MSC(BOT) device under Win8.1. The test that I did is: leaving the device behind the root port and reboot the system. With MSFT inbox xHCI stack, the drive letter doesn’t pop up but in our stack(xHCI + Hub) the drive letter windows pops up when system reboot is done.
When I look at the USB bus trace, there are several STALL in transactions since this device doesn’t support some SCSI commands. Through roughly calculation, it takes ~50 seconds when the drive letter pops up since I start rebooting the system.
But the interesting thing is, it takes ~40 seconds when the main Win8.1 window shows up but it takes ~55 seconds in MSFT stack. It looks like the MSFT stack tries to hold the main window until this device get full enumerated. But I don’t know how to find the problem in our driver.
I compare the USB bus trace between ours and MSFT stack, I don’t see any obvious problems.
Can anybody give some comments or suggestions?
Thanks!