From: Takashi Iwai <tiwai@suse.de>
To: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dave Airlie <airlied@gmail.com>,
Intel Graphics Development <intel-gfx@lists.freedesktop.org>,
DRI Development <dri-devel@lists.freedesktop.org>,
LKML <linux-kernel@vger.kernel.org>,
linux-fbdev-devel@lists.sourceforge.net,
Alan Cox <alan@lxorguk.ukuu.org.uk>,
Alan Cox <alan@linux.intel.com>
Subject: Re: [PATCH 1/2] fb: Rework locking to fix lock ordering on takeover
Date: Wed, 23 Jan 2013 17:38:42 +0100 [thread overview]
Message-ID: <s5hk3r3etwt.wl%tiwai@suse.de> (raw)
In-Reply-To: <1358958309-5342-2-git-send-email-daniel.vetter@ffwll.ch>
At Wed, 23 Jan 2013 17:25:08 +0100,
Daniel Vetter wrote:
>
> From: Alan Cox <alan@lxorguk.ukuu.org.uk>
>
> Adjust the console layer to allow a take over call where the caller already
> holds the locks. Make the fb layer lock in order.
>
> This s partly a band aid, the fb layer is terminally confused about the
> locking rules it uses for its notifiers it seems.
>
> Signed-off-by: Alan Cox <alan@linux.intel.com>
> [danvet: Tiny whitespace cleanup.]
> Reported-and-tested-by: Hugh Dickins <hughd@google.com>
> Reported-and-tested-by: Sasha Levin <levinsasha928@gmail.com>
> References: https://lkml.org/lkml/2012/10/25/516
> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
FYI, the latest patch of this is found in mm tree:
http://ozlabs.org/~akpm/mmots/broken-out/fb-rework-locking-to-fix-lock-ordering-on-takeover.patch
Also I hit the same problem in another code paths (for unbind and
unregister):
http://marc.info/?t=135309396400003&r=1&w=2
My additional patch is found in mm tree, too:
http://ozlabs.org/~akpm/mmots/broken-out/fb-yet-another-band-aid-for-fixing-lockdep-mess.patch
Takashi
next prev parent reply other threads:[~2013-01-23 16:38 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-23 16:25 [PATCH 0/2] fbcon+i915 locking fixes Daniel Vetter
2013-01-23 16:25 ` [PATCH 1/2] fb: Rework locking to fix lock ordering on takeover Daniel Vetter
2013-01-23 16:38 ` Takashi Iwai [this message]
2013-01-23 16:49 ` Daniel Vetter
2013-01-23 16:25 ` [PATCH 2/2] drm/i915: fixup per-crtc locking in intel_release_load_detect_pipe Daniel Vetter
2013-01-24 9:55 ` Daniel Vetter
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