From: Oliver Neukum <oliver@neukum.org>
To: Duncan Sands <baldrick@free.fr>, Alan Stern <stern@rowland.harvard.edu>
Cc: David Brownell <david-b@pacbell.net>, Vince <fuzzy77@free.fr>,
"Randy.Dunlap" <rddunlap@osdl.org>, <mfedyk@matchmail.com>,
<zwane@holomorphy.com>, <linux-kernel@vger.kernel.org>,
USB development list <linux-usb-devel@lists.sourceforge.net>
Subject: Re: [linux-usb-devel] Re: [OOPS, usbcore, releaseintf] 2.6.0-test10-mm1
Date: Thu, 11 Dec 2003 11:19:00 +0100 [thread overview]
Message-ID: <200312111119.00289.oliver@neukum.org> (raw)
In-Reply-To: <200312111045.11275.baldrick@free.fr>
Am Donnerstag, 11. Dezember 2003 10:45 schrieb Duncan Sands:
> > > > > __usb_set_configuration - lockless version
> > > > > usb_set_configuration - locked version
> > > >
> > > > Partially done.
> > > > That's what the _physical version of usb_reset_device() is about.
> > >
> > > Unfortunately, usb_physical_reset_device calls usb_set_configuration
> > > which takes dev->serialize.
> >
> > That is bad, but the solution is obvious.
> > All such operations need a _physical version.
> > At first sight this may look less elegant than some lock dropping schemes,
> > but it is a solution that produces obviously correct code paths with
> > respect to locking.
>
> Hi Oliver, I agree, except that there are several layers of locking: dev->serialize
> but also the bus rwsem. So does "physical" mean no subsys.rwsem or no
> dev->serialize or both?
"physical" means no locking at all. It's the caller's responsibility.
> int usb_reset_device(struct usb_device *udev)
> {
> struct device *gdev = &udev->dev;
> int r;
>
> down_read(&gdev->bus->subsys.rwsem);
> r = usb_physical_reset_device(udev);
> up_read(&gdev->bus->subsys.rwsem);
>
> return r;
> }
That's what the core cares about. No probe() while a reset is in
progress. Taking the semaphore ensures that.
Regards
Oliver
next prev parent reply other threads:[~2003-12-11 10:21 UTC|newest]
Thread overview: 113+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-11-26 16:51 [kernel panic @ reboot] 2.6.0-test10-mm1 Vince
2003-11-26 17:16 ` Zwane Mwaikambo
2003-11-26 17:34 ` Vince
2003-11-26 17:35 ` Randy.Dunlap
2003-11-26 17:40 ` Zwane Mwaikambo
2003-11-26 17:54 ` Vince
2003-11-26 18:18 ` Zwane Mwaikambo
2003-11-26 23:37 ` Mike Fedyk
2003-11-26 23:41 ` Vince
2003-12-03 0:03 ` Randy.Dunlap
2003-12-03 0:31 ` Mike Fedyk
2003-12-03 0:27 ` Randy.Dunlap
2003-12-03 13:28 ` Vince
2003-12-03 19:12 ` Zwane Mwaikambo
2003-12-04 1:01 ` Vince
2003-12-04 1:34 ` Mike Fedyk
2003-12-04 4:11 ` Randy.Dunlap
2003-12-04 10:59 ` [OOPS, usbcore, releaseintf] 2.6.0-test10-mm1 Vince
2003-12-04 11:14 ` Duncan Sands
2003-12-04 16:57 ` Randy.Dunlap
2003-12-05 7:38 ` Duncan Sands
2003-12-05 10:11 ` Vince
2003-12-05 10:18 ` Duncan Sands
2003-12-05 10:34 ` Vince
2003-12-07 0:25 ` Duncan Sands
2003-12-07 21:09 ` Vince
2003-12-07 21:24 ` Duncan Sands
2003-12-07 22:24 ` Vince
2003-12-07 22:54 ` Vince
2003-12-08 10:10 ` Duncan Sands
2003-12-08 16:03 ` [linux-usb-devel] " David Brownell
2003-12-08 16:15 ` Duncan Sands
2003-12-08 16:31 ` Alan Stern
2003-12-08 17:20 ` David Brownell
2003-12-08 17:59 ` Duncan Sands
2003-12-08 18:35 ` Alan Stern
2003-12-08 19:53 ` Duncan Sands
2003-12-08 21:32 ` Alan Stern
2003-12-08 21:55 ` Duncan Sands
2003-12-08 23:09 ` Alan Stern
2003-12-09 10:23 ` Duncan Sands
2003-12-09 15:55 ` Alan Stern
2003-12-09 20:36 ` Duncan Sands
2003-12-09 10:36 ` Duncan Sands
2003-12-09 16:08 ` Alan Stern
2003-12-09 20:24 ` Duncan Sands
2003-12-09 10:49 ` Duncan Sands
2003-12-09 15:47 ` Alan Stern
2003-12-09 21:12 ` Duncan Sands
2003-12-09 21:58 ` Alan Stern
2003-12-09 22:07 ` Duncan Sands
2003-12-09 22:25 ` David Brownell
2003-12-09 22:33 ` Duncan Sands
2003-12-10 3:12 ` David Brownell
2003-12-10 3:43 ` Alan Stern
2003-12-10 13:12 ` Duncan Sands
2003-12-10 15:13 ` Alan Stern
2003-12-10 15:30 ` Greg KH
2003-12-10 16:02 ` Duncan Sands
2003-12-10 20:53 ` Greg KH
2003-12-11 8:49 ` Duncan Sands
2003-12-11 9:23 ` Greg KH
2003-12-11 9:29 ` Duncan Sands
2003-12-10 17:25 ` Alan Stern
2003-12-10 20:46 ` Greg KH
2003-12-10 21:08 ` Greg KH
2003-12-11 2:10 ` Vince
2003-12-11 6:46 ` Greg KH
2003-12-10 22:08 ` Alan Stern
2003-12-11 6:47 ` Greg KH
2003-12-10 4:31 ` Vince
2003-12-10 1:49 ` Greg KH
2003-12-10 13:22 ` Duncan Sands
2003-12-10 16:20 ` Oliver Neukum
2003-12-10 16:49 ` Duncan Sands
2003-12-10 16:58 ` Oliver Neukum
2003-12-11 9:45 ` Duncan Sands
2003-12-11 10:19 ` Oliver Neukum [this message]
2003-12-11 21:43 ` Duncan Sands
2003-12-11 22:57 ` Oliver Neukum
2003-12-11 23:30 ` Duncan Sands
2003-12-12 0:02 ` David Brownell
2003-12-10 17:34 ` David Brownell
2003-12-10 17:54 ` Duncan Sands
2003-12-10 18:19 ` Alan Stern
2003-12-11 9:36 ` Duncan Sands
2003-12-11 15:19 ` Alan Stern
2003-12-11 21:23 ` Duncan Sands
2003-12-12 15:46 ` Alan Stern
2003-12-11 21:29 ` Duncan Sands
2003-12-12 16:18 ` Alan Stern
2003-12-12 18:37 ` David Brownell
2003-12-12 19:17 ` Alan Stern
2003-12-12 19:45 ` David Brownell
2003-12-12 20:48 ` Alan Stern
2003-12-12 21:01 ` Oliver Neukum
2003-12-12 21:27 ` Alan Stern
2003-12-12 23:36 ` Oliver Neukum
2003-12-13 1:10 ` Alan Stern
2003-12-13 11:52 ` Oliver Neukum
2003-12-12 18:50 ` Oliver Neukum
2003-12-10 19:43 ` David Brownell
2003-12-11 9:21 ` Duncan Sands
2003-12-10 17:21 ` David Brownell
2003-12-11 9:42 ` Duncan Sands
2003-12-12 2:21 ` David Brownell
2003-12-12 8:47 ` Duncan Sands
2003-12-12 15:35 ` bill davidsen
2003-12-05 0:08 ` [kernel panic @ reboot] 2.6.0-test10-mm1 Zwane Mwaikambo
2003-11-27 0:59 ` [kernel panic @ reboot in usbcore] 2.6.0-test10-mm1 (culprit: modem_run) Vince
2003-11-27 3:13 ` Zwane Mwaikambo
2003-11-27 8:14 ` Vince
2003-11-27 8:11 ` Duncan Sands
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