Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753968Ab1DFAn7 (ORCPT ); Tue, 5 Apr 2011 20:43:59 -0400 Received: from imr3.ericy.com ([198.24.6.13]:45090 "EHLO imr3.ericy.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752596Ab1DFAn5 (ORCPT ); Tue, 5 Apr 2011 20:43:57 -0400 Date: Tue, 5 Apr 2011 17:43:12 -0700 From: Guenter Roeck To: Natarajan Gurumoorthy CC: Jean Delvare , Wim Van Sebroeck , Mike Waychison , "lm-sensors@lm-sensors.org" , "linux-kernel@vger.kernel.org" , "linux-watchdog@vger.kernel.org" Subject: Re: [PATCH] Make all it87 drivers SMP safe. Message-ID: <20110406004312.GA21882@ericsson.com> References: <1302038697-28985-1-git-send-email-natg@google.com> <20110405223814.GA21350@ericsson.com> <20110406000528.GB21350@ericsson.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2103 Lines: 57 On Tue, Apr 05, 2011 at 08:13:50PM -0400, Natarajan Gurumoorthy wrote: > Guenter, > ? ? ? How would you partition it out? Are you suggesting that we do > the following: > > Patch1: > ? ?drivers/hwmon/Kconfig ? ? ? ? ?| ? ?1 + > ? ?drivers/hwmon/it87.c ? ? ? ? ? | ? 14 ++++++++++++- > > Patch2: > ? ?drivers/watchdog/Kconfig ? ? ? | ? 12 +++++++++++ > ? ?drivers/watchdog/Makefile ? ? ?| ? ?1 + > ? ?drivers/watchdog/it8712f_wdt.c | ? 10 ++++---- > ? ?drivers/watchdog/it87_lock.c ? | ? 27 +++++++++++++++++++++++++ > ? ?drivers/watchdog/it87_wdt.c ? ?| ? 42 ++++++--------------------------------- > > Patch3: > ? ?include/linux/it87_lock.h ? ? ?| ? 28 ++++++++++++++++++++++++++ > No, not really. The include file is part of the locking code, and the sequence is wrong. I personally would introduce the lock in the 1st patch. This would affect drivers/watchdog/it87_lock.c include/linux/it87_lock.h drivers/watchdog/Makefile drivers/watchdog/Kconfig The second patch would update the watchdog driver, affecting drivers/watchdog/Kconfig drivers/watchdog/it8712f_wdt.c and the last patch would update the hwmon driver. drivers/hwmon/Kconfig drivers/hwmon/it87.c Others may argue that patch 1 and 2 (introducing the lock and updating the watchdog driver) should be in a single patch, since the lock alone does not do anything without being used. This is a matter of opinion and really depends on the maintainer of the watchdog subsystem. Note that your patch has practical problems. If I disable WATCHDOG but enable the IT87 hwmon driver, I get: warning: (SENSORS_IT87) selects IT87_LOCK which has unmet direct dependencies (WATCHDOG) during configuration, and undefined references to it87_io_lock when linking. So it looks like you might want to consider moving the locking code to a location outside the watchdog code. Thanks, Guenter -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/