Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753542AbbEGKBT (ORCPT ); Thu, 7 May 2015 06:01:19 -0400 Received: from mout.kundenserver.de ([212.227.126.130]:55163 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753130AbbEGKBP (ORCPT ); Thu, 7 May 2015 06:01:15 -0400 From: Arnd Bergmann To: Brian Norris Cc: linux-mtd@lists.infradead.org, Dmitry Torokhov , Anatol Pomazao , Ray Jui , Corneliu Doban , Jonathan Richardson , Scott Branden , Florian Fainelli , =?utf-8?B?UmFmYcWCIE1pxYJlY2tp?= , bcm-kernel-feedback-list@broadcom.com, Dan Ehrenberg , Gregory Fong , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Kevin Cernekee Subject: Re: [PATCH v3 06/10] mtd: brcmstb_nand: add SoC-specific support Date: Thu, 07 May 2015 12:01:02 +0200 Message-ID: <20781942.cIPodTiNzG@wuerfel> User-Agent: KMail/4.11.5 (Linux/3.16.0-10-generic; KDE/4.11.5; x86_64; ; ) In-Reply-To: <20150506204910.GJ32500@ld-irv-0074> References: <1430935194-7579-1-git-send-email-computersforpeace@gmail.com> <7101952.uOJDgn7tgf@wuerfel> <20150506204910.GJ32500@ld-irv-0074> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-Provags-ID: V03:K0:Y+9yTwdBR5JHCzzoE1o8nVH6oo+6YvBYBNMHEKmZUH06PUvYDdd 0wwmS8Y079uR1wYpanYLZtTLsJ6auW7MQkzb+DpuT90xL8xGE4aLFyuXCeqjKInCPsczG81 /VA8jffjzEcSHctmU70mW/E6BU5e/ksvop5qAuDz2bjTjN2UhkuuiurXEbQrmk+LJQ7MbZe Bi63PB6Mtfmse/tAzs1gg== X-UI-Out-Filterresults: notjunk:1; Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2838 Lines: 65 On Wednesday 06 May 2015 13:49:10 Brian Norris wrote: > On Wed, May 06, 2015 at 09:12:43PM +0200, Arnd Bergmann wrote: > > On Wednesday 06 May 2015 10:59:50 Brian Norris wrote: > > > + /* > > > + * Some SoCs integrate this controller (e.g., its interrupt bits) in > > > + * interesting ways > > > + */ > > > + if (of_property_read_bool(dn, "brcm,nand-soc")) { > > > + struct device_node *soc_dn; > > > + > > > + soc_dn = of_parse_phandle(dn, "brcm,nand-soc", 0); > > > + if (!soc_dn) > > > + return -ENODEV; > > > + > > > + ctrl->soc = devm_brcmnand_probe_soc(dev, soc_dn); > > > + if (!ctrl->soc) { > > > + dev_err(dev, "could not probe SoC data\n"); > > > + of_node_put(soc_dn); > > > + return -ENODEV; > > > + } > > > + > > > + ret = devm_request_irq(dev, ctrl->irq, brcmnand_irq, 0, > > > + DRV_NAME, ctrl); > > > + > > > + /* Enable interrupt */ > > > + ctrl->soc->ctlrdy_set_enabled(ctrl->soc, true); > > > + > > > + of_node_put(soc_dn); > > > + } else { > > > + /* Use standard interrupt infrastructure */ > > > + ret = devm_request_irq(dev, ctrl->irq, brcmnand_ctlrdy_irq, 0, > > > + DRV_NAME, ctrl); > > > + } > > > > > > > It looks to me like this should be handled as a nested irqchip, so the node > > you look up gets used as the "interrupt-parent" instead, making the behavior > > of this SoC transparent to the nand driver. > > You snipped the rest of the patch, which involves more than just IRQ > handling. The same registers touch both interrupts and data bus endian > configuration, so it can't possibly be done transparently to the NAND > driver. Anything else in there? The bus configuration would just involve writing a constant value in some register, right? Doing that in the irqchip is also a bit ugly, but may still be better overall than doing it the way you have above. > > We recently merged nested irqdomain support as well, which might help here, > > or might not be needed. > > I'm not familiar with nested irqdomains. Do they address anything like > the above problem? The problem that nested irqdomains address is when an interrupt is handled by two irqchips, in particular when one irqchip handles a virtual interrupt number that was claimed by another irqchip already. Arnd -- 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/