From patchwork Fri Mar 15 11:21:56 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Javier Martinez Canillas X-Patchwork-Id: 2275971 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by patchwork1.kernel.org (Postfix) with ESMTP id A59EA3FC8A for ; Fri, 15 Mar 2013 11:25:01 +0000 (UTC) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1UGSiP-0002GE-F7; Fri, 15 Mar 2013 11:22:25 +0000 Received: from mail-ia0-x22f.google.com ([2607:f8b0:4001:c02::22f]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1UGSiL-0002FG-5j for linux-arm-kernel@lists.infradead.org; Fri, 15 Mar 2013 11:22:23 +0000 Received: by mail-ia0-f175.google.com with SMTP id y26so830788iab.34 for ; Fri, 15 Mar 2013 04:22:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=x-received:mime-version:in-reply-to:references:from:date:message-id :subject:to:cc:content-type; bh=xns/KJUowsYnkfRQJTl8qLM+qB+cY1FftzjI5Oe971U=; b=d1VOcZVGemwNy9uT3k0JBCJQC56vmVzGkyyKqQ5JQf5sUZZqGJgIKkMPOqFySmmA06 Mm2R0VmwPlKDg0NdjHd5sBoPXMrdQ5lEtq3hipHj+ZfwPjDjG1ojqr2hzM06lQco/MCr 978TiyCyMkdA0NL3gLgBwPpqrABlG9WxiuaprFw8yHHLJW/1e7ObcvhZAS/lVF1e7jPh OjNXLkeG+RLSCVFo681O65wlFwV7/ywMGyLgy63h7mKplCir8T+XlvDRuHTL13HkRgTH kwKI4ZHGAAusnhGvvme3jUMdOLM6mfjkEreB9fHAj0+AbT0JNwdbSB2wALiA0qYebIyq WqXA== X-Received: by 10.50.181.136 with SMTP id dw8mr851788igc.39.1363346536643; Fri, 15 Mar 2013 04:22:16 -0700 (PDT) MIME-Version: 1.0 Received: by 10.64.71.2 with HTTP; Fri, 15 Mar 2013 04:21:56 -0700 (PDT) In-Reply-To: <51391F41.5000303@ti.com> References: <1329321854-24490-1-git-send-email-b-cousson@ti.com> <1329321854-24490-4-git-send-email-b-cousson@ti.com> <4F44FA56.7020000@gmail.com> <4F44FC37.2000701@ti.com> <4F452484.5080503@gmail.com> <74CDBE0F657A3D45AFBB94109FB122FF17BD8BC6C1@HQMAIL01.nvidia.com> <4F47AD08.4030504@ti.com> <512D39DA.7020306@ti.com> <512D3AB1.1080202@wwwdotorg.org> <512D3EC2.6050408@ti.com> <20130302200524.D230F3E1571@localhost> <51391F41.5000303@ti.com> From: Javier Martinez Canillas Date: Fri, 15 Mar 2013 12:21:56 +0100 Message-ID: Subject: Re: [PATCH 3/5] gpio/omap: Add DT support to GPIO driver To: Grant Likely X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130315_072221_269965_20574CFA X-CRM114-Status: GOOD ( 28.05 ) X-Spam-Score: -2.0 (--) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-2.0 points) pts rule name description ---- ---------------------- -------------------------------------------------- 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (martinez.javier[at]gmail.com) -0.0 SPF_PASS SPF: sender matches SPF record -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature Cc: Stephen Warren , Stephen Warren , Kevin Hilman , "devicetree-discuss@lists.ozlabs.org" , Jon Hunter , "linux-omap@vger.kernel.org" , Tarun Kanti DebBarma , "linux-arm-kernel@lists.infradead.org" X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org On Fri, Mar 8, 2013 at 12:14 AM, Jon Hunter wrote: > > On 03/02/2013 02:05 PM, Grant Likely wrote: >> On Tue, 26 Feb 2013 17:01:22 -0600, Jon Hunter wrote: >>> >>> On 02/26/2013 04:44 PM, Stephen Warren wrote: >>>> On 02/26/2013 03:40 PM, Jon Hunter wrote: >>>>> On 02/26/2013 04:01 AM, Javier Martinez Canillas wrote: >>>>> Are you requesting the gpio anywhere? If not then this is not going to >>>>> work as-is. This was discussed fairly recently [1] and the conclusion >>>>> was that the gpio needs to be requested before we can use as an interrupt. >>>> >>>> That seems wrong; the GPIO/IRQ driver should handle this internally. The >>>> Ethernet driver shouldn't know/care whether the interrupt it's given is >>>> some form of dedicated interrupt or a GPIO-based interrupt, and even if >>>> it somehow did, there's no irq_to_gpio() any more, so the driver can't >>>> tell which GPIO ID it should request, unless it's given yet another >>>> property to represent this. >>> >>> I agree that ideally this should be handled internally. Did you read the >>> discussion on the thread that I referenced [1]? If you have any thoughts >>> we are open to ideas :-) >> >> I'm on an airplane right now, but I agree 100% with Stephen. I'll try to >> remember to go read that thread and respond, but this falls firmly in >> the its-a-bug category for me. :-) > > Grant, did you have chance to review the thread [1]? > > I am trying to figure out if we should just take the original patch > proposed in the thread (although Linus had some objections) or look at > alternative solutions such as adding a irq_chip request as Stephen > suggested. > > Cheers > Jon > > [1] comments.gmane.org/gmane.linux.ports.arm.omap/92192 Hello Grant, I was wondering if you have any opinions on this issue. As Jon said, Stephen proposed [2] to add a request callback to irq_chip. I hacked a very simple and naive patch (just to validate the idea) and is working. The GPIO bank is requested before calling the gpio-omap .irq_set_type function handler (gpio_irq_type) when using a GPIO as an IRQ on a DT. So is not necessary to call it explicitly anymore. But the patch is obviously wrong (to say the least) since the kernel runtime locking validator complains that "possible circular locking dependency detected" I just wanted to know if I was on the right track or completely lost here. Thanks a lot and best regards, javier [2]: http://www.mail-archive.com/linux-omap@vger.kernel.org/msg85592.html ret = __irq_set_trigger(desc, irq, diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c index 159f5c5..f5feb43 100644 --- a/drivers/gpio/gpio-omap.c +++ b/drivers/gpio/gpio-omap.c @@ -807,6 +807,13 @@ static void gpio_unmask_irq(struct irq_data *d) spin_unlock_irqrestore(&bank->lock, flags); } +static int gpio_irq_request(struct irq_data *d) +{ + struct gpio_bank *bank = irq_data_get_irq_chip_data(d); + + return gpio_request(irq_to_gpio(bank, d->irq), "gpio-irq"); +} + static struct irq_chip gpio_irq_chip = { .name = "GPIO", .irq_shutdown = gpio_irq_shutdown, @@ -815,6 +822,7 @@ static struct irq_chip gpio_irq_chip = { .irq_unmask = gpio_unmask_irq, .irq_set_type = gpio_irq_type, .irq_set_wake = gpio_wake_enable, + .irq_request = gpio_irq_request, }; /*---------------------------------------------------------------------*/ diff --git a/include/linux/irq.h b/include/linux/irq.h index bc4e066..2aeaa24 100644 --- a/include/linux/irq.h +++ b/include/linux/irq.h @@ -303,6 +303,7 @@ struct irq_chip { void (*irq_shutdown)(struct irq_data *data); void (*irq_enable)(struct irq_data *data); void (*irq_disable)(struct irq_data *data); + int (*irq_request)(struct irq_data *data); void (*irq_ack)(struct irq_data *data); void (*irq_mask)(struct irq_data *data); diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index fa17855..07c20f7 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -1093,6 +1093,13 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) if (!shared) { init_waitqueue_head(&desc->wait_for_threads); + if (desc->irq_data.chip->irq_request) { + ret = desc->irq_data.chip->irq_request(&desc->irq_data); + + if (ret) + goto out_mask; + } + /* Setup the type (level, edge polarity) if configured: */ if (new->flags & IRQF_TRIGGER_MASK) {