Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760237AbZD1NQY (ORCPT ); Tue, 28 Apr 2009 09:16:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752972AbZD1NQK (ORCPT ); Tue, 28 Apr 2009 09:16:10 -0400 Received: from relay.atmel.no ([80.232.32.139]:62751 "EHLO relay.atmel.no" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754657AbZD1NQI (ORCPT ); Tue, 28 Apr 2009 09:16:08 -0400 Date: Tue, 28 Apr 2009 15:13:53 +0200 From: Hans-Christian Egtvedt To: Atsushi Nemoto Cc: alessandro.zummo@towertech.it, 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: <20090428151353.0c15c5fc@hcegtvedt.norway.atmel.com> 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: Atmel X-Mailer: Claws Mail 3.6.1 (GTK+ 2.16.1; i486-pc-linux-gnu) 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: 1031 Lines: 29 On Sat, 25 Apr 2009 02:06:12 +0900 (JST) Atsushi Nemoto wrote: > 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. > AVR32 has interrupts disabled during the interrupt handler, so AFAICT the rtc-at32ap700x.c should be fine. -- Best regards, Hans-Christian Egtvedt -- 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/