From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030884Ab2CFPCF (ORCPT ); Tue, 6 Mar 2012 10:02:05 -0500 Received: from out5-smtp.messagingengine.com ([66.111.4.29]:56654 "EHLO out5-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030778Ab2CFPCD (ORCPT ); Tue, 6 Mar 2012 10:02:03 -0500 X-Sasl-enc: StPf9RxNL3qj0A0gVX0quVJCaUh6fsPaLU1uLyOPg7e3 1331046122 Message-ID: <4F562775.2010501@ladisch.de> Date: Tue, 06 Mar 2012 16:04:21 +0100 From: Clemens Ladisch User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:10.0.2) Gecko/20120216 Thunderbird/10.0.2 MIME-Version: 1.0 To: Thomas Gleixner CC: akpm@linux-foundation.org, maglyx@gmail.com, Arnd Bergmann , John Stultz , LKML Subject: Re: [patch 4/4] hpet: factor timer allocate from open References: <20120305230755.35019A02EB@akpm.mtv.corp.google.com> In-Reply-To: Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Thomas Gleixner wrote: > On Mon, 5 Mar 2012, akpm@linux-foundation.org wrote: >> From: Magnus Lynch >> Subject: hpet: factor timer allocate from open >> >> The current implementation of the /dev/hpet driver couples opening the >> device with allocating one of the (scarce) timers (aka comparators). This >> is a limitation in that the main counter may be valuable to applications >> seeking a high-resolution timer who have no use for the interrupt >> generating functionality of the comparators. >> >> This patch alters the open semantics so that when the device is opened, no >> timer is allocated. Operations that depend on a timer being in context >> implicitly attempt allocating a timer, to maintain backward compatibility. > > AFAICT, there is only fasync which calls hpet_alloc_timer(). All other > functions are broken by this chage. Indeed. There was another call in hpet_ioctl_common(), but it appears that one somehow got dropped. Magnus, is this the patch that you submitted and have tested? Regards, Clemens