On Thu, May 9, 2019 at 5:17 PM Chris Chiu [off-list ref] wrote:

I need the vif because there's seems no easy way to get RSSI. Please
suggest if there's any better idea for this. I believe multiple vifs is for AP
mode (with more than 1 virtual AP/SSIDs) and the Station+AP coexist
mode. But the rtl8xxxu driver basically supports only Station mode.

Yes, the driver only lets you create station interfaces, but it lets
you create several of them.
I'm not sure if that is intentional (and meaningful), or if its a bug.
Maybe you can experiment with multiple station interfaces and see if
it works in a meaningful way?

Daniel