From: Paul Mundt <lethal@linux-sh.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Wu Zhangjin <wuzhangjin@gmail.com>,
linux-media@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-mips@linux-mips.org, Krzysztof Helt <krzysztof.h1@wp.pl>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
"Rafael J. Wysocki" <rjw@sisk.pl>,
Andrew Morton <akpm@linux-foundation.org>,
Ralf Baechle <ralf@linux-mips.org>, ???? <yanh@lemote.com>,
zhangfx <zhangfx@lemote.com>
Subject: Re: [BUG] drivers/video/sis: deadlock introduced by "fbdev: add mutex for fb_mmap locking"
Date: Mon, 6 Jul 2009 00:01:35 +0900 [thread overview]
Message-ID: <20090705150134.GB8326@linux-sh.org> (raw)
In-Reply-To: <alpine.LFD.2.01.0907050756280.3210@localhost.localdomain>
On Sun, Jul 05, 2009 at 07:56:56AM -0700, Linus Torvalds wrote:
>
>
> On Sun, 5 Jul 2009, Paul Mundt wrote:
> > break;
> > fb_info->node = i;
> > mutex_init(&fb_info->lock);
> > - mutex_init(&fb_info->mm_lock);
>
> Why not "lock" as well?
>
I had that initially, but matroxfb will break if we do that, and
presently nothing cares about trying to take ->lock that early on.
->mm_lock was a special case as the lock/unlock pairs were sprinkled
around well before initialization, while in the ->lock case all of the
lock/unlock pairs are handled internally by the fbmem code (at least a
quick grep does not show any drivers using it on their own).
next prev parent reply other threads:[~2009-07-05 15:01 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-07-05 9:11 [BUG] drivers/video/sis: deadlock introduced by "fbdev: add mutex for fb_mmap locking" Wu Zhangjin
2009-07-05 14:19 ` Linus Torvalds
2009-07-05 14:52 ` Paul Mundt
2009-07-05 14:56 ` Linus Torvalds
2009-07-05 15:01 ` Paul Mundt [this message]
2009-07-05 15:19 ` Linus Torvalds
2009-07-05 15:25 ` Paul Mundt
2009-07-05 15:32 ` Linus Torvalds
2009-07-05 16:18 ` Krzysztof Helt
2009-07-06 1:13 ` Wu Zhangjin
2009-07-06 14:50 ` Krzysztof Helt
2009-07-06 16:29 ` Linus Torvalds
2009-07-05 16:43 ` Krzysztof Helt
2009-07-05 15:05 ` Krzysztof Helt
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