From mboxrd@z Thu Jan 1 00:00:00 1970 From: Martin Peres Subject: Re: [PATCH] pm/fan: drop the fan lock in fan_update() before rescheduling Date: Tue, 18 Mar 2014 14:36:22 +0100 Message-ID: <53284BD6.7080700@free.fr> References: <1394754503-22066-1-git-send-email-martin.peres@free.fr> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1"; Format="flowed" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <1394754503-22066-1-git-send-email-martin.peres-GANU6spQydw@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: nouveau-bounces-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org Sender: "Nouveau" To: nouveau-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org Cc: Martin Peres List-Id: nouveau.vger.kernel.org Le 14/03/2014 00:48, Martin Peres a =E9crit : > From: Martin Peres > > This should fix a deadlock that has been reported to us where fan_update() > would hold the fan lock and try to grab the alarm_program_lock to resched= ule > an update. On an other CPU, the alarm_program_lock would have been taken > before calling fan_update(), leading to a deadlock. > > Reported-by: Marcin Slusarz > Signed-off-by: Martin Peres Tested-by: Timoth=E9e Ravier Cc: # 3.9+ This problem dates back to fa37e8dda2617d48fbc6b17dd6e986e7f4c2bc8b. It = would seem it got released in 3.9.