Re: [PATCH] usb: f_mass_storage: test whether thread is running before starting another

[Alan Stern]

On Wed, 6 Apr 2016, Michal Nazarewicz wrote:

> On Tue, Apr 05 2016, Alan Stern wrote:
> > Suppose one usb_function is carrying out an I/O operation while
> > another one in the same config gets a Set-Interface request from the
> > host.
> 
> That cannot happen.  A single instance of mass_storage cannot be added
> twice to the same configuration.
> 
> Â To be more precise, not via configfs.  A legacy gadget could do that,
>   but that would be a bug in that legacy driver, not f_mass_storage.
>   Moreover, no current legacy gadgets do that though so IMO this is an
>   academic discussion.

Okay.  Then I suggest adding this explanation to the patch description.

BTW, is configfs capable of adding a single instance twice in different 
configs?  Or is that again something only legacy gadgets can do?

Alan Stern