Re: [PATCH] usb: core: support interface node for simple USB devices

[Johan Hovold]

On Wed, Jan 22, 2025 at 05:17:36PM +0000, POPESCU Catalin wrote:
> On 22/01/2025 14:53, Greg KH wrote:

> > serdev can not use usb-serial devices due to the lack of hotplugging, so
> > why is this an issue?  I thought that just would not work.
> 
> Well, I can say that on 6.12.0 it's working :
> 
> [    0.929493] usb 1-1: new full-speed USB device number 2 using xhci-hcd
> [    5.906574] usbcore: registered new interface driver ftdi_sio
> [    5.906632] usbserial: USB Serial support registered for FTDI USB 
> Serial Device
> [    5.906727] ftdi_sio 1-1:1.0: FTDI USB Serial Device converter detected
> [    5.906842] usb 1-1: Detected FT-X
> [    5.907809] serial serial0: tty port ttyUSB0 registered

You'd need to patch USB serial too for this to happen so this in not
mainline 6.12.

And if the port is open during disconnect you'd see a bunch of warnings
because the serdev tty port implementation does not handle hangups.

Johan