From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754534AbYIICwv (ORCPT ); Mon, 8 Sep 2008 22:52:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752401AbYIICwm (ORCPT ); Mon, 8 Sep 2008 22:52:42 -0400 Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:51882 "EHLO sunset.davemloft.net" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1752224AbYIICwm (ORCPT ); Mon, 8 Sep 2008 22:52:42 -0400 Date: Mon, 08 Sep 2008 19:52:35 -0700 (PDT) Message-Id: <20080908.195235.200905674.davem@davemloft.net> To: david-b@pacbell.net Cc: James.Bottomley@hansenpartnership.com, torvalds@linux-foundation.org, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-parisc@vger.kernel.org, alessandro.zummo@towertech.it Subject: Re: [PATCH] fix RTC_CLASS regression with PARISC From: David Miller In-Reply-To: <200809081755.26148.david-b@pacbell.net> References: <200809081629.21125.david-b@pacbell.net> <20080908.164427.216880550.davem@davemloft.net> <200809081755.26148.david-b@pacbell.net> X-Mailer: Mew version 6.1 on Emacs 22.1 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 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 From: David Brownell Date: Mon, 8 Sep 2008 17:55:25 -0700 > On Monday 08 September 2008, David Miller wrote: > > From: David Brownell > > Date: Mon, 8 Sep 2008 16:29:20 -0700 > > > > > That said, there's a bit of unresolved stuff around NTP hooks > > > in the kernel. Some patches are pending to let thtem work with > > > the RTC framework -- where writing an RTC may need to sleep, > > > for example because the RTC is on an I2C or SPI bus. And > > > then there's the discussion of whether that shouldn't all be > > > handled by NTPD anyway, no special kernel support desired. > > > Alessandro has opinions there. ;) > > > > My update_persistent_clock() on sparc64 is: > > > > int update_persistent_clock(struct timespec now) > > { > > struct rtc_device *rtc = rtc_class_open("rtc0"); > > I'd be tempted to cache that ... notice how you never > close it, too. That will goof lots of refcounts... Well if I cache it then we'll hold it forever and that's not so nice right? I'm going to put the missing rtc_close() in there for now to fix the leak. I'm happy to cache this if you think it's warranted, but then this is like saying that the refcount doesn't matter :-) > =============== CUT ON THE DOTTED LINE ================== > Subject: ntp: let update_persistent_clock() sleep > From: "Maciej W. Rozycki" I see, as Paul mentioned this is needed for stuff like RTCs behind I2C. This change isn't in Linus's tree yet.