From mboxrd@z Thu Jan 1 00:00:00 1970 From: Uwe =?iso-8859-1?Q?Kleine-K=F6nig?= Subject: Re: [PATCH 6/7] spi/mpc8xxx: don't check platform_get_irq's return value against zero Date: Thu, 17 Dec 2009 14:05:49 +0100 Message-ID: <20091217130549.GA9032@pengutronix.de> References: <1260979809-24811-2-git-send-email-u.kleine-koenig@pengutronix.de> <1260979809-24811-3-git-send-email-u.kleine-koenig@pengutronix.de> <1260979809-24811-4-git-send-email-u.kleine-koenig@pengutronix.de> <1260979809-24811-5-git-send-email-u.kleine-koenig@pengutronix.de> <1260979809-24811-6-git-send-email-u.kleine-koenig@pengutronix.de> <20091216163229.GA26350@oksana.dev.rtsoft.ru> <20091216174904.GB26325@pengutronix.de> <20091216182034.GA7590@oksana.dev.rtsoft.ru> <20091216191839.GA23614@pengutronix.de> <20091216193745.GA20429@oksana.dev.rtsoft.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: linux-kernel@vger.kernel.org, David Vrabel , Greg Kroah-Hartman , David Brownell , Grant Likely , Kumar Gala , Andrew Morton , spi-devel-general@lists.sourceforge.net, Linus Torvalds To: Anton Vorontsov Return-path: Content-Disposition: inline In-Reply-To: <20091216193745.GA20429@oksana.dev.rtsoft.ru> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-spi.vger.kernel.org Hi Anton, On Wed, Dec 16, 2009 at 10:37:45PM +0300, Anton Vorontsov wrote: > On Wed, Dec 16, 2009 at 08:18:39PM +0100, Uwe Kleine-K=F6nig wrote: > [...] > > > > I'm a bit annoyed as this is the third time[1] this month this = irq0 > > > > discussion pops up for me. I think people see that irq0 is inv= olved > > > > somehow, start wailing and stop seeing the issues being fixed. > > >=20 > > > For this particular driver, there is NO issue whatsoever. It is > > > only used for PowerPC, which has VIRQ0 =3D=3D invalid IRQ. And no= te > > > that there still could be HWIRQ0 on PowerPC, but it is *never* > > > mapped to VIRQ0. > > Yes, there is an issue. If the platform device doesn't have a reso= urce > > specifing the irq, platform_get_irq returns -ENXIO. So in the driv= er > > (unsigned)(-ENXIO) is passed to mpc8xxx_spi_probe as (!(-ENXIO)) is > > false and so the error isn't catched. >=20 > If you look into how we create the platform device, you'll notice > that -ENXIO isn't possible. > It's in arch/powerpc/platforms/83xx/mpc832x_rdb.c:of_fsl_spi_probe(), > which is a legacy interface that I'd like to be removed anyway. >=20 > Though, if you want to fix the inconsistency in the platform device > API, then I'd suggest to fix the platform_get_irq(). The driver itsel= f > is correct. With platform_get_irq as it is today, the check in irq =3D platform_get_irq(pdev, 0); if (!irq) return -EINVAL; is non-sense as !irq always evaluates to 0. If your argue that the resources are right, then the logical consequence is to strip down plat_mpc8xxx_spi_probe to just struct spi_master *master; master =3D mpc8xxx_spi_probe(&pdev->dev, platform_get_resource(pdev, IORESOURCE_MEM, 0) platform_get_irq(pdev, 0)); if (IS_ERR(master)) return PTR_ERR(master); return 0; Best regards Uwe --=20 Pengutronix e.K. | Uwe Kleine-K=F6nig = | Industrial Linux Solutions | http://www.pengutronix.= de/ |