Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1162629AbWLGSIj (ORCPT ); Thu, 7 Dec 2006 13:08:39 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1163135AbWLGSIj (ORCPT ); Thu, 7 Dec 2006 13:08:39 -0500 Received: from pollux.ds.pg.gda.pl ([153.19.208.7]:2770 "EHLO pollux.ds.pg.gda.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1162629AbWLGSIh (ORCPT ); Thu, 7 Dec 2006 13:08:37 -0500 Date: Thu, 7 Dec 2006 18:08:33 +0000 (GMT) From: "Maciej W. Rozycki" To: Jeff Garzik , Andy Fleming cc: Andrew Morton , Linus Torvalds , David Howells , rdreier@cisco.com, ben.collins@ubuntu.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH] Export current_is_keventd() for libphy In-Reply-To: <457849E2.3080909@garzik.org> Message-ID: References: <20061206234942.79d6db01.akpm@osdl.org> <1165125055.5320.14.camel@gullible> <20061203011625.60268114.akpm@osdl.org> <20061205123958.497a7bd6.akpm@osdl.org> <6FD5FD7A-4CC2-481A-BC87-B869F045B347@freescale.com> <20061205132643.d16db23b.akpm@osdl.org> <20061205135753.9c3844f8.akpm@osdl.org> <20061206075729.b2b6aa52.akpm@osdl.org> <20061206224207.8a8335ee.akpm@osdl.org> <9392.1165487379@redhat.com> <20061207024211.be739a4a.akpm@osdl.org> <457849E2.3080909@garzik.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1092 Lines: 31 On Thu, 7 Dec 2006, Jeff Garzik wrote: > Looking into libphy's workqueue stuff, it has the following sequence: > > disable interrupts > schedule_work() > > ... time passes ... > ... workqueue routine is called ... > > enable interrupts > handle interrupt > > I really have to question if a workqueue was the best choice of direction for > such a sequence. You don't want to put off handling an interrupt, with > interrupts disabled, for a potentially unbounded amount of time. This is because to ack the interrupt in the device the MDIO bus has to be accessed and I gather for some implementations it may be too obnoxiously slow for the interrupt context to cope with. Note that only the interrupt line used for the PHY is disabled (though obviously with consequences to any sharers). Andy, could you please comment? Maciej - 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/