From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755085Ab0IMTFN (ORCPT ); Mon, 13 Sep 2010 15:05:13 -0400 Received: from smtp-out003.kontent.com ([81.88.40.217]:34714 "EHLO smtp-out003.kontent.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755053Ab0IMTFK (ORCPT ); Mon, 13 Sep 2010 15:05:10 -0400 From: Oliver Neukum To: Alan Stern Subject: Re: [linux-pm] wacom + runtime PM = AA deadlock Date: Mon, 13 Sep 2010 21:05:38 +0200 User-Agent: KMail/1.13.5 (Linux/2.6.34-12-desktop; KDE/4.4.4; x86_64; ; ) Cc: Jiri Slaby , Dmitry Torokhov , pingc@wacom.com, "linux-pm" , Linux kernel mailing list , linux-input@vger.kernel.org References: In-Reply-To: MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201009132105.38204.oliver@neukum.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am Montag, 13. September 2010, 17:17:54 schrieb Alan Stern: > On Mon, 13 Sep 2010, Oliver Neukum wrote: > > > PM in this driver looks broken. Please try this. > > > > In short you want to drop the PM reference and depend on remote > > wakeup and busy marking for this driver. Currently it gets a reference > > on every open() but never drops it. > > > > For locking you depend on the PM core's internal lock. You simply > > make sure you have a PM reference during open() and close() > > Is there any point in resuming the device during close() just in order > to kill the interrupt URB? It seems counterproductive -- if the device > had been suspended then there wouldn't be any interrupt URB to kill in > the first place. Suppose the device does not support remote wakeup. It would never be autosuspended while it is open, but simply resetting the flag would never reach the PM layer. Regards Oliver