Re: [PATCH v5 2/3] usb: gadget: udc: core: Invoke usb_gadget_connect only when started

[Alan Stern]

On Wed, May 31, 2023 at 03:40:26PM -0700, Badhri Jagan Sridharan wrote:
> On Wed, May 31, 2023 at 10:55 AM Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote:
> >
> > On Wed, May 31, 2023 at 04:02:02AM +0000, Badhri Jagan Sridharan wrote:
> > > usb_udc_connect_control() does not check to see if the udc has already
> > > been started. This causes gadget->ops->pullup to be called through
> > > usb_gadget_connect() when invoked from usb_udc_vbus_handler() even
> > > before usb_gadget_udc_start() is called. Guard this by checking for
> > > udc->started in usb_udc_connect_control() before invoking
> > > usb_gadget_connect().
> >
> > After a merged version of patches 1/3 and 3/3 have been applied, it
> > seems like most of this will not be needed any more.  Maybe not any of
> > it.
> 
> Without the connect_lock introduced in this patch, wouldn't the
> usb_gadget_connect()/
> usb_gadget_disconnect() through soft_connect_store() race against
> usb_gadget_connect()/ usb_gadget_disconnect() through
> usb_udc_connect_control() ?

Okay, yes, that's a good point.  It needs to be mentioned in the patch 
description so that people will understand it is the real reason for 
this change.

Alan Stern