From: Oliver Neukum <oliver@neukum.name>
To: "John Tyner" <jtyner@cs.ucr.edu>, "Greg KH" <greg@kroah.com>
Cc: <linux-kernel@vger.kernel.org>, linux-usb-devel@lists.sourceforge.net
Subject: Re: Vicam/3com homeconnect usb camera driver
Date: Mon, 7 Oct 2002 11:43:21 +0200 [thread overview]
Message-ID: <m17yUpC-006hzVC@Mail.ZEDAT.FU-Berlin.DE> (raw)
In-Reply-To: <000e01c26d8f$987153f0$0a00a8c0@refresco>
> Attached is a patch against 2.5.40 with __dev* uses removed and the error
> checking in the open routine fixed.
>
> Let me know if the ordering of the video_unregister_device and tasklet_kill
> is still an issue.
Well, here we go again, there are other issues as well.
There's a race between open() and disconnect(). The best way to deal
with it is to introduce a common semaphore for all devices the driver handles
and to take it as the first thing open() and disconnect() do and release it
as the last thing. In addition every device needs a flag to show that it has
been opened and a flag to show that it has been unplugged. Alternatively
you could introduce device states, being "present and unused", "present and
used" and "unplugged but used". As this needs to be checked in release(), it
needs to take the semaphore as well.
Regards
Oliver
next prev parent reply other threads:[~2002-10-07 10:03 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-10-06 2:58 John Tyner
2002-10-06 10:11 ` Oliver Neukum
2002-10-06 17:35 ` John Tyner
2002-10-06 22:01 ` Oliver Neukum
2002-10-06 23:25 ` John Tyner
2002-10-07 4:55 ` Oliver Neukum
2002-10-07 9:43 ` Oliver Neukum [this message]
2002-10-07 21:51 ` John Tyner
[not found] ` <001901c26e8d$3f62f850$0a00a8c0@refresco>
2002-10-08 16:30 ` [linux-usb-devel] " Oliver Neukum
-- strict thread matches above, loose matches on Subject: below --
2002-10-06 21:32 John Tyner
2002-10-06 21:44 ` Oliver Neukum
2002-10-04 3:59 John Tyner
2002-10-04 4:50 ` Greg KH
2002-10-04 5:05 ` John Tyner
2002-10-04 5:22 ` Greg KH
2002-10-06 2:57 ` John Tyner
2002-10-06 21:06 ` Pavel Machek
2002-10-07 18:43 ` John Tyner
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