Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754122Ab1BVVdV (ORCPT ); Tue, 22 Feb 2011 16:33:21 -0500 Received: from opensource.wolfsonmicro.com ([80.75.67.52]:58369 "EHLO opensource2.wolfsonmicro.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751734Ab1BVVdU (ORCPT ); Tue, 22 Feb 2011 16:33:20 -0500 Date: Tue, 22 Feb 2011 21:33:19 +0000 From: Mark Brown To: john stultz Cc: rtc-linux@googlegroups.com, LKML , Thomas Gleixner , Alessandro Zummo , Marcelo Roberto Jimenez Subject: Re: [rtc-linux] [PATCH 04/10] RTC: Cleanup rtc_class_ops->read_alarm() Message-ID: <20110222213319.GI31611@opensource.wolfsonmicro.com> References: <1298332538-31216-5-git-send-email-john.stultz@linaro.org> <20110222023452.GB18299@sirena.org.uk> <1298343333.4222.36.camel@work-vm> <1298362178.4222.57.camel@work-vm> <20110222181647.GA25569@opensource.wolfsonmicro.com> <1298404268.9215.39.camel@work-vm> <20110222200046.GD31611@opensource.wolfsonmicro.com> <1298406174.9215.71.camel@work-vm> <20110222210522.GG31611@opensource.wolfsonmicro.com> <1298409673.9215.84.camel@work-vm> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1298409673.9215.84.camel@work-vm> X-Cookie: You now have Asian Flu. User-Agent: Mutt/1.5.17+20080114 (2008-01-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1069 Lines: 20 On Tue, Feb 22, 2011 at 01:21:13PM -0800, john stultz wrote: > But if you just mean trying to keep multiple alarms scheduled across > resets, I don't think that is something we can emulate (since the kernel > doesn't have any other persistent storage). But due to the lack of > consistency in RTC hardware, I don't think its a reasonable expectation > for applications to have. I'm saying that I've got concerns about providing that functionality at all as it's going to be a pure software at runtime thing - the kernel can't do anything here that userspace couldn't already do and there are things that userspace can do that the kernel can't. If the hardware could do it then great but otherwise it feels like you'd be better off with a program in userspace owning the hardware and dealing with the resource contention. -- 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/