From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964977Ab3BMVeL (ORCPT ); Wed, 13 Feb 2013 16:34:11 -0500 Received: from mail-da0-f41.google.com ([209.85.210.41]:63595 "EHLO mail-da0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751861Ab3BMVeJ (ORCPT ); Wed, 13 Feb 2013 16:34:09 -0500 Date: Wed, 13 Feb 2013 13:34:05 -0800 From: Dmitry Torokhov To: Arnd Bergmann Cc: Heiko Carstens , Takashi Iwai , axboe@kernel.dk, cbou@mail.ru, davem@davemloft.net, dwmw2@infradead.org, grant.likely@secretlab.ca, gregkh@linuxfoundation.org, jkosina@suse.cz, jslaby@suse.cz, khali@linux-fr.org, mchehab@redhat.com, perex@perex.cz, sameo@linux.intel.com, w.sang@pengutronix.de, linux-kernel@vger.kernel.org, sebott@linux.vnet.ibm.com, gerald.schaefer@de.ibm.com, schwidefsky@de.ibm.com Subject: Re: [PATCH 12/15] sound: add missing HAS_IOPORT and GENERIC_HARDIRQS dependencies Message-ID: <20130213213405.GA23390@core.coreip.homeip.net> References: <1360167843-3587-1-git-send-email-heiko.carstens@de.ibm.com> <20130206181242.GA3281@osiris> <201302062156.55910.arnd@arndb.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <201302062156.55910.arnd@arndb.de> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 06, 2013 at 09:56:55PM +0000, Arnd Bergmann wrote: > On Wednesday 06 February 2013, Heiko Carstens wrote: > > > > I haven't looked into it, but I doubt if that is possible without large > > effort, if at all. s390 doesn't have any irq chips, nor something like > > edge or level triggered irqs. > > Instead we have floating interrupts. Does that fit into the concept of > > GENERIC_HARDIRQS at all? > > If so, we can give it a try, sure. But that won't happen any time soon. > > > > Or are you simply proposing we should have both, our own irq handling plus > > GENERIC_HARDIRQS with dummy functions? > > I think you should use GENERIC_HARDIRQ just for PCI, and rename the s390 > interrupt handling to something that does not conflict. I understand > that the concepts are quite different, but with PCI support, you actually > do get all the weird interrupt hardware. > More importantly, some features provided by GENERIC_HARDIRQ are replacing > the traditional interfaces now, e.g. devm_request_irq() is actually > recommended over request_irq() for normal drivers these days, as it > simplifies the error handling. I would be very careful with this statement. While devm_request_irq() does simplify error handling in several cases I have also seen countless examples when it was used with non devm_*-managed structures that are freed by hand opening race window where interrupts can be delivered and use structure that is already freed. Thanks. -- Dmitry