I understand this feature is creating instability in other area. However - 1. the problem will remain same when enable the usb-wakeup feature form kernel or user-space or udev rule, and as long LE device is
connected.
There is a slight difference of leaving the decision to the user (or to userspace) or forcing it down the throat of everyone by adding it to the kernel.
Your statement "I understand this feature is creating instability in other area" should really be a wakeup call. It almost sounds like you are aware that it is causing problems, but you don't care because it fits _your_ needs. I hope that is not the case, but if it is, please keep in mind that you are not the only user of the Linux kernel.
No I don't know what is the problem here... As mentioned, keeping wake up enable(default) is same as BR/EDR mouse connected. Hence you will see the same platform behavior when BR/EDR mouse connected, and Without this patch.
Thanks, Guenter