Re: Data toggles not reset on "set configuration" for ports handled by "xhci_hcd" driver

[Alan Stern <stern@rowland.harvard.edu>]

On Wed, Aug 26, 2020 at 11:37:50AM +0300, Mathias Nyman wrote:
> On 25.8.2020 18.10, Alan Stern wrote:
> > There's got to be a better way to do this, something that doesn't 
> > involve so much code duplication.  For instance, maybe we could make 
> > this routine and usb_set_configuration() both call a new 
> > __usb_set_config(), with an extra flag telling the routine whether to 
> > change the interface devices and bindings.
> 
> I agree that this needs cleaning up, this code was intended for testing.
> 
> It allows us to call usb_hcd_alloc_bandwidth() once with a configuration
> and with the old endpoint pointers still intact, leading to one configure
> endpoint command for xhci with the relevant drop and add endpoint flags set,
> all in one go.
> 
> Looks like the last part usb_disable_device() does similar endpoint code
> churning to flush, disable, drop, and remove endpoints. May we could start
> by turning that code into some useful helper first?

usb_disable_device() is _supposed_ to be the useful helper!  :-)  But 
yes, it could be split into two pieces.

I still think it would be worthwhile to combine usb_set_configuration() 
and usb_reset_configuration() into one routine, since they have to do a 
lot of the same things.

Alan Stern