From: Gu Zheng <guz.fnst@cn.fujitsu.com>
To: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>,
Linux Fbdev development list <linux-fbdev@vger.kernel.org>,
linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [RFC PATCH RESEND] fb: reorder the lock sequence to fix a potential lockdep
Date: Thu, 31 Oct 2013 01:17:05 +0000 [thread overview]
Message-ID: <5271AF91.4090109@cn.fujitsu.com> (raw)
In-Reply-To: <5270EB85.1030103@ti.com>
Hi Tomi,
On 10/30/2013 07:20 PM, Tomi Valkeinen wrote:
> Hi,
>
> On 2013-10-28 08:01, Gu Zheng wrote:
>> Following commits:
>> 50e244cc79 fb: rework locking to fix lock ordering on takeover
>> e93a9a8687 fb: Yet another band-aid for fixing lockdep mess
>> 054430e773 fbcon: fix locking harder
>>
>> reworked locking to fix related lock ordering on takeover, and introduced console_lock
>> into fbmem, but it seems that the new lock sequence(fb_info->lock ---> console_lock)
>> is against with the one in console_callback(console_lock ---> fb_info->lock), and leads to
>> a potential deadlock as following:
>
> A quick grep shows that there are other places than fbmem.c which use
> lock_fb_info and console_lock, for example drivers/video/sh_mobile_lcdcfb.c.
Yes, thanks for your reminder, I'll fix them all in the next version.
Regards,
Gu
>
> Tomi
>
>
prev parent reply other threads:[~2013-10-31 1:17 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-28 6:01 [RFC PATCH RESEND] fb: reorder the lock sequence to fix a potential lockdep Gu Zheng
2013-10-30 3:18 ` Gu Zheng
2013-10-30 11:20 ` Tomi Valkeinen
2013-10-31 1:17 ` Gu Zheng [this message]
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