[PATCH] usb: gadget: aspeed_udc: fix handling of tx_len == 0

[Neal Liu]

> On Fri, 2022-06-24 at 07:46 +0000, Neal Liu wrote:
> > >
> > Hi Ben, This UDC is the independent IP. The ast2600 board can run
> > aspeed-vhub & aspeed_udc simultaneously with different USB port.
> > I think it's no need to restruct the code in vhub.
> 
> But is it a copy of the same base IP block ? IE, is the fundamental HW interface
> of the independent UDC operating the same way with the same register layout
> as one of the ports of the vHUB ?
> 
> I don't like having multiple drivers for the same hardware... if it's different
> enough, then let's keep it separate, but if not, we should definitely split the udc
> from the existing vhub code so that the same driver can operate standalone or
> beneath a vhub.
> 

Based on ast2600 hardware design, it's similar, but not exactly the same.
I need more time to extract the differences and evaluate it if it could utilize vhub.

> Cheers,
> Ben.