Re: Disconnect race in Gadget core

[Peter Chen <peter.chen@kernel.org>]

On 21-05-16 10:51:51, Alan Stern wrote:
> On Sun, May 16, 2021 at 12:43:58PM +0300, Felipe Balbi wrote:
> > 
> > Hi,
> > 
> > Alan Stern <stern@rowland.harvard.edu> writes:
> > >
> > > If it's okay to call those functions in interrupt context then the 
> > > kerneldoc definitely should be updated.  However, I don't see why you 
> > > would want to make DELAYED_STATUS mandatory.  If all the necessary work 
> > > can be done in the set_alt handler, why not return the status 
> > > immediately?
> > 
> > because we avoid a special case. Instead of having magic return value to
> > mean "Don't do anything until I enqueue a request" we can just make that
> > an assumption, i.e. gadget driver *must* enqueue requests for data and
> > status stages.
> 
> Okay.  But that would require auditing every gadget/function driver to 
> ensure that they _do_ enqueue status stage requests

CDNS3 UDC doesn't enqueue status stage by SW, instead, SW tells HW to do
it by setting registers.

-- 

Thanks,
Peter Chen