Re: [PATCH v5 01/46] usb: gadget: encapsulate endpoint claiming mechanism

From: Felipe Balbi
Date: Thu Aug 20 2015 - 12:49:03 EST


On Thu, Aug 20, 2015 at 06:28:14PM +0200, Robert Baldyga wrote:
> Hi Felipe,
>
> On 08/20/2015 05:35 PM, Felipe Balbi wrote:
> [...]
> >just letting you know that this regresses all gadget drivers making them
> >try to disable previously disabled endpoints and enable previously
> >enabled endpoints.
> >
> >I have a possible fix (see below) but then it shows a problem on the
> >host side when using with g_zero (see further below):
> >
> >commit 3b8932100aacb6cfbffe288ca93025d8b8430c00
> >Author: Felipe Balbi <balbi@xxxxxx>
> >Date: Wed Aug 19 18:05:27 2015 -0500
> >
> > usb: gadget: fix ep->claimed lifetime
> >
> > In order to fix a regression introduced by commit
> > cc476b42a39d ("usb: gadget: encapsulate endpoint
> > claiming mechanism") we have to introduce a simple
> > helper to check if a particular is enabled or not.
> >
> > After that, we need to move ep->claimed lifetime to
> > usb_ep_enable() and usb_ep_disable() since those
> > are the only functions which actually enable and
> > disable endpoints.
> >
> > A follow-up patch will come to drop all driver_data
> > checks from function drivers, since those are, now,
> > pointless.
> >
> > Fixes: cc476b42a39d ("usb: gadget: encapsulate endpoint
> > claiming mechanism")
> > Cc: Robert Baldyga <r.baldyga@xxxxxxxxxxx>
> > Signed-off-by: Felipe Balbi <balbi@xxxxxx>
> >
> >diff --git a/drivers/usb/gadget/epautoconf.c b/drivers/usb/gadget/epautoconf.c
> >index 978435a51038..ad45070cd76f 100644
> >--- a/drivers/usb/gadget/epautoconf.c
> >+++ b/drivers/usb/gadget/epautoconf.c
> >@@ -126,7 +126,6 @@ found_ep:
> > ep->address = desc->bEndpointAddress;
> > ep->desc = NULL;
> > ep->comp_desc = NULL;
> >- ep->claimed = true;
>
> Removing this line causes autoconfig can return the same endpoint many
> times. This probably causes problems with g_zero.
>
> I will try to fix it ASAP.

I was considering the same thing, but the lifetime of ->claimed doesn't
look correct to me either way. Note that once the flag is enabled, it
won't get disabled by most gadget drivers.

--
balbi

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