Re: Virtual hub, resets etc...

[Benjamin Herrenschmidt <benh@kernel.crashing.org>]

On Sat, 2019-07-06 at 14:37 -0400, Alan Stern wrote:
> On Sat, 6 Jul 2019, Benjamin Herrenschmidt wrote:
> 
> > On Fri, 2019-07-05 at 10:08 -0400, Alan Stern wrote:
> > > On Fri, 5 Jul 2019, Benjamin Herrenschmidt wrote:
> 
> > > > Sure but it would be nice if the mass storage dealt with
> -ESHUTDOWN
> > > > properly and stopped :-) Or other errors... if the UDC HW for
> example
> > > > dies for some reason, mass storage will lockup.
> > > 
> > > I suppose we could add code to check for this case and handle
> it, 
> > > although I'm not sure what would be the right thing to do.  Delay
> for 
> > > one second and try again?  Disable the gadget until the host does
> a 
> > > reset?
> > 
> > I think just stop it until the next reset yes.
> 
> Can you test this patch?

Not for a few days, I'm away from the machine and that test requires me
being physically present, but I will when I'm back.

Thanks !

Cheers,
Ben.

> Alan Stern
> 
> 
> 
> Index: usb-devel/drivers/usb/gadget/function/f_mass_storage.c
> ===================================================================
> --- usb-devel.orig/drivers/usb/gadget/function/f_mass_storage.c
> +++ usb-devel/drivers/usb/gadget/function/f_mass_storage.c
> @@ -552,13 +552,14 @@ static int start_transfer(struct fsg_dev
>  
>                 /* We can't do much more than wait for a reset */
>                 req->status = rc;
> +               if (rc == -ESHUTDOWN)
> +                       fsg->common->running = 0;
>  
>                 /*
>                  * Note: currently the net2280 driver fails zero-
> length
>                  * submissions if DMA is enabled.
>                  */
> -               if (rc != -ESHUTDOWN &&
> -                               !(rc == -EOPNOTSUPP && req->length ==
> 0))
> +               else if (!(rc == -EOPNOTSUPP && req->length == 0))
>                         WARNING(fsg, "error in submission: %s -->
> %d\n",
>                                         ep->name, rc);
>         }