From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757129Ab2IGNnK (ORCPT ); Fri, 7 Sep 2012 09:43:10 -0400 Received: from mail-ee0-f46.google.com ([74.125.83.46]:61996 "EHLO mail-ee0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753315Ab2IGNnG (ORCPT ); Fri, 7 Sep 2012 09:43:06 -0400 Date: Fri, 7 Sep 2012 14:43:01 +0100 From: Lee Jones To: Arnd Bergmann Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, STEricsson_nomadik_linux@list.st.com, linus.walleij@stericsson.com, Samuel Ortiz Subject: Re: [PATCH 15/19] mfd: Don't convert just one IRQ using irqdomain if a range is provided Message-ID: <20120907134259.GJ29601@gmail.com> References: <1347016499-29354-1-git-send-email-lee.jones@linaro.org> <201209071235.41785.arnd@arndb.de> <20120907124611.GD29601@gmail.com> <201209071337.26587.arnd@arndb.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <201209071337.26587.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 Fri, Sep 07, 2012 at 01:37:26PM +0000, Arnd Bergmann wrote: > On Friday 07 September 2012, Lee Jones wrote: > > On Fri, Sep 07, 2012 at 12:35:41PM +0000, Arnd Bergmann wrote: > > > On Friday 07 September 2012, Lee Jones wrote: > > > > MFD core code attempts to convert specified hardware (local) IRQ > > > > numbers to virtual-IRQs, which something Linux can understand. This > > > > works great when only one IRQ is specified. However, converting > > > > entire ranges is currently unsupported. If this occurs we issue a > > > > kernel warning to inform the user of this, but we continue to > > > > convert the first specified IRQ anyway and replace the range. This > > > > is not the correct behaviour. This patch ensures that if a range > > > > is specified, it is left untouched. > > > > > > > > CC: Samuel Ortiz > > > > Signed-off-by: Lee Jones > > > > > > I don't see the advantage of the change. The warning already tells > > > us that the input to mfd_add_device was incorrect, so nothing the > > > function does can reliably fix it. Leaving the resource empty > > > is just as wrong as listing only the first interrupt. > > > > My thinking was to leave them in a range, then have the target driver > > convert each entry in the range manually. But what you're saying is > > that no registration should be attempted using ranges at all? What if > > the range was vast? Surely a resource array a few hundred lines long > > isn't correct either? My immediate example would be "GPIO_INT6", which > > has 31 lines. Do you want them all splitting out individually? > > The examples I had seen before were all just ranges of two interrupts, > and in those cases it was clear that splitting them would be best. > > In the exampled of the ab8500-gpio driver, it looks like the resource is > not actually being used, and the gpio driver implements its own irq_chip, > so maybe we can get away with not solving this problem for now. Understood. I'd still feel more comfortable if we didn't trash the range. I think it would be best to show the warning, and leave the range for its target driver to take care - hence the patch. ... but it's your call. -- Lee Jones Linaro ST-Ericsson Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog