Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755051AbZDXTl3 (ORCPT ); Fri, 24 Apr 2009 15:41:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751272AbZDXTlV (ORCPT ); Fri, 24 Apr 2009 15:41:21 -0400 Received: from mx0.towertech.it ([213.215.222.73]:46118 "HELO mx0.towertech.it" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751822AbZDXTlU (ORCPT ); Fri, 24 Apr 2009 15:41:20 -0400 Date: Fri, 24 Apr 2009 21:41:17 +0200 From: Alessandro Zummo To: Atsushi Nemoto Cc: rtc-linux@googlegroups.com, david-b@pacbell.net, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, hcegtvedt@atmel.com, vapier@gentoo.org, rongkai.zhan@windriver.com, balajirrao@openmoko.org, broonie@opensource.wolfsonmicro.com Subject: Re: [rtc-linux] Re: [PATCH] rtc: Make rtc_update_irq callable with irqs enabled Message-ID: <20090424214117.76bc3dda@i1501.lan.towertech.it> In-Reply-To: <20090425.020612.92585418.anemo@mba.ocn.ne.jp> References: <200904240410.52543.david-b@pacbell.net> <20090424131334.10959f78@i1501.lan.towertech.it> <20090425.014850.93020801.anemo@mba.ocn.ne.jp> <20090425.020612.92585418.anemo@mba.ocn.ne.jp> Organization: Tower Technologies X-Mailer: Sylpheed X-This-Is-A-Real-Message: Yes 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 Content-Length: 856 Lines: 29 On Sat, 25 Apr 2009 02:06:12 +0900 (JST) Atsushi Nemoto wrote: > RTC alarm interrupt handler takes rtc->irq_lock by spin_lock() > > 2. A timer interrupt handler calls rtc_uie_timer() for UIE emulation > > 3. rtc_uie_timer() waits on rtc->irq_lock .... deadlock! > > Oops, this is wrong. This deadlock cannot happen since > rtc_uie_timer() will be called in bh (softirq) context, not interrupt > context. Correct. And we have only one irq handler per driver. Anything else? -- Best regards, Alessandro Zummo, Tower Technologies - Torino, Italy http://www.towertech.it -- 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/