Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760740AbZDXRGb (ORCPT ); Fri, 24 Apr 2009 13:06:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759914AbZDXRGO (ORCPT ); Fri, 24 Apr 2009 13:06:14 -0400 Received: from mba.ocn.ne.jp ([122.1.235.107]:50546 "EHLO smtp.mba.ocn.ne.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758761AbZDXRGN (ORCPT ); Fri, 24 Apr 2009 13:06:13 -0400 Date: Sat, 25 Apr 2009 02:06:12 +0900 (JST) Message-Id: <20090425.020612.92585418.anemo@mba.ocn.ne.jp> To: alessandro.zummo@towertech.it 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 From: Atsushi Nemoto In-Reply-To: <20090425.014850.93020801.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> X-Fingerprint: 6ACA 1623 39BD 9A94 9B1A B746 CA77 FE94 2874 D52F X-Pgp-Public-Key: http://wwwkeys.pgp.net/pks/lookup?op=get&search=0x2874D52F X-Mailer: Mew version 5.2 on Emacs 21.4 / 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 Content-Length: 786 Lines: 20 On Sat, 25 Apr 2009 01:48:50 +0900 (JST), Atsushi Nemoto wrote: > Here is a possible example: > > 1. 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. Anyway, I just posted updated patch. Please take a look. Thanks. --- Atsushi Nemoto -- 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/