Re: [PATCH] usb: gadget: fix possible regression introduced with ep->claimed

From: Felipe Balbi
Date: Fri Aug 21 2015 - 16:22:57 EST


Hi,

On Fri, Aug 21, 2015 at 10:00:50AM -0500, Felipe Balbi wrote:
> On Fri, Aug 21, 2015 at 11:01:29AM +0200, Robert Baldyga wrote:
> > This patch fixes possible regression introduced by patch reworking endpoint
> > claiming mechanism. It restores setring ep->driver_data to NULL in
> > usb_ep_autoconfig_reset(), which was removed by patch [1].
> >
> > [1] commit cc476b42a39d ("usb: gadget: encapsulate endpoint claiming
> > mechanism")
> >
> > Reported-by: Felipe Balbi <balbi@xxxxxx>
> > Signed-off-by: Robert Baldyga <r.baldyga@xxxxxxxxxxx>
> > ---
> >
> > Hi Felipe,
> >
> > I was not able to reproduce the problem that you have described (functions
> > trying to enable eps that are already enabled, and disable eps that are
> > already disabled), but I have analysed the problem and I have concluded
>
> it happens with all, you can't see it because dwc3 (only) has a WARN()
> for when an endpoint is enabled and has previously been enabled
> (drivers/usb/dwc3/gadget.c). If you track your endpoint's state
> regarding being enabled or not, you can add a WARN() to see the error.
>
> > that the only possible cause of regression can be that my patch removed
> > setting ep->driver_data to NULL in usb_ep_autoconfig_reset() function.
> > Because of this change initial state of ep->driver_data could be non-NULL
> > value, which could change behavoiur of some functions. I can't imagine
> > any other possible cause of regression introduced by such simple patch.
>
> yeah, I'll test this later.

this has been running for many hours and I couldn't find any problems so
far. Just in case, I'll keep it running, but I doubt we'll find
anything. Once -rc1 is tagged, I'll send this to Greg.

thanks

--
balbi

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