linux-kernel - Re: [PATCH v1] USB:gadget: Fix a warning while loading g_mass

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <Pine.LNX.4.44L0.1406040953400.15745-100000@netrider.rowland.org>
Date:	Wed, 4 Jun 2014 09:56:36 -0400 (EDT)
From:	Alan Stern <stern@...land.harvard.edu>
To:	"Yang,Wei" <Wei.Yang@...driver.com>
cc:	Peter Chen <Peter.Chen@...escale.com>,
	Michal Nazarewicz <mina86@...a86.com>,
	Andrzej Pietrasiewicz <andrzej.p@...sung.com>,
	Felipe Balbi <balbi@...com>,
	"gregkh@...uxfoundation.org" <gregkh@...uxfoundation.org>,
	USB list <linux-usb@...r.kernel.org>,
	Kernel development list <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v1] USB:gadget: Fix a warning while loading g_mass_storage

On Wed, 4 Jun 2014, Yang,Wei wrote:

> On 06/04/2014 09:45 AM, Peter Chen wrote:
> >   
> >> commit d18f7116a5ddb8263fe62b05ad63e5ceb5875791
> >> Author: Robert Baldyga <r.baldyga@...sung.com>
> >> Date:   Thu Nov 21 13:49:18 2013 +0100
> >>
> >>       usb: gadget: s3c-hsotg: fix disconnect handling
> >>
> >>       This patch moves s3c_hsotg_disconnect function call from USBSusp
> >> interrupt
> >>       handler to SET_ADDRESS request handler.
> >>
> > It is a little strange we call gadget's disconnect at SET_ADDRESS?
> > How the udc calls gadget driver the disconnection has happened when
> > the usb cable is disconnected from the host?
> >
> > Usually, we call gadget's disconnect at two situations
> >
> > - udc's reset handler if udc's speed is not UNKNOWN, it is usually happened
> > when the host sends reset after enumeration.
> > - udc's disconnect handler, it is usually happened when the usb cable
> > is disconnected from host.
> 
> Hmm, usually the two situations, but according to the commit log, s3c 
> hsotg does not support Disconnected interrupt for device mode,
> so the second situation does not happen for s3c hsotg, therefore, he has 
> to disconnect the connection before it is connected again.

Why does he need to do that?  Why not just skip the disconnect 
notification if the hardware can't detect a disconnect?

It makes no sense at all to call a disconnect handler from within the 
SET_ADDRESS routine.

Alan Stern

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/