From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?ISO-8859-1?Q?Richard_R=F6jfors?= Subject: Re: [PATCH 1/2] tsc2007: remove HR timer Date: Thu, 09 Jul 2009 18:51:56 +0200 Message-ID: <4A56202C.9020809@mocean-labs.com> References: <4A40C288.2060702@mocean-labs.com> <20090625142010.bd656a9d.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from av12-2-sn2.hy.skanova.net ([81.228.8.186]:60297 "EHLO av12-2-sn2.hy.skanova.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759720AbZGIQwF (ORCPT ); Thu, 9 Jul 2009 12:52:05 -0400 In-Reply-To: <20090625142010.bd656a9d.akpm@linux-foundation.org> Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: Andrew Morton Cc: linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, kwangwoo.lee@gmail.com, thierry.reding@avionic-design.de, soni.trilok@gmail.com On 6/25/09 11:20 PM, Andrew Morton wrote: > On Tue, 23 Jun 2009 13:54:48 +0200 > Richard R__jfors wrote: > >> This patch removes the HR timer, since it's bad to do synchronous I2C >> in the HR timer callback context. The new implementation makes use >> of the global workqueue. The work is scheduled every 5ms when polling >> rather than 5 us. >> > > "it's bad" isn't a very good description of the problem which the patch > fixes. The problem is that the synchronous I2C calls in HR-timer callback context might end up in a deadlock. > > This matters. People wish to make decisions about whether this patch > is needed in 2.6.29.x, 2.6.30.x, 2.6.31, 2.6.32, etc. Without knowing > the effects of the problem which the patch fixes, we cannot make that > decision! > >> + /* cancel any work */ >> + cancel_delayed_work(&ts->work); >> + > > Should this have been cancel_delayed_work_sync()? It should, I will post a new patch shortly which should be applied after these two which fixes this. --Richard