From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7043EC433E9 for ; Thu, 4 Mar 2021 12:25:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 472BE64F1E for ; Thu, 4 Mar 2021 12:25:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240526AbhCDMZW (ORCPT ); Thu, 4 Mar 2021 07:25:22 -0500 Received: from mga04.intel.com ([192.55.52.120]:9798 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240513AbhCDMZK (ORCPT ); Thu, 4 Mar 2021 07:25:10 -0500 IronPort-SDR: NITUvqY5MIMeCmiRevvDk7DMmIjdU/w2ufIMHe5vsSL8CoJg7/3Fqipoz/XGQEZ7nmowDO4Vqo orVBAIiwy5tg== X-IronPort-AV: E=McAfee;i="6000,8403,9912"; a="184992977" X-IronPort-AV: E=Sophos;i="5.81,222,1610438400"; d="scan'208";a="184992977" Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Mar 2021 04:23:24 -0800 IronPort-SDR: eOIw4Ik0iMb/jRHUYypfI2+783AgoiX1bJE2+eS4wgH0VHXUiPJDqAGGbcT7WXZb9UM0XC4vQt ED2lzCxSaAPg== X-IronPort-AV: E=Sophos;i="5.81,222,1610438400"; d="scan'208";a="384425630" Received: from smile.fi.intel.com (HELO smile) ([10.237.68.40]) by orsmga002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Mar 2021 04:23:22 -0800 Received: from andy by smile with local (Exim 4.94) (envelope-from ) id 1lHn0i-009sFs-9v; Thu, 04 Mar 2021 14:23:20 +0200 Date: Thu, 4 Mar 2021 14:23:20 +0200 From: Andy Shevchenko To: Linus Walleij Cc: Mika Westerberg , "open list:GPIO SUBSYSTEM" , ACPI Devel Maling List , "linux-kernel@vger.kernel.org" , Bartosz Golaszewski Subject: Re: [PATCH v1 4/4] gpiolib: Reuse device's fwnode to create IRQ domain Message-ID: References: <20210302153451.50593-1-andriy.shevchenko@linux.intel.com> <20210302153451.50593-4-andriy.shevchenko@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 04, 2021 at 09:06:08AM +0100, Linus Walleij wrote: > On Wed, Mar 3, 2021 at 10:35 AM Andy Shevchenko > wrote: > > On Wed, Mar 03, 2021 at 10:22:02AM +0100, Linus Walleij wrote: > > > > But this: > > > > > > > @@ -1504,15 +1497,14 @@ static int gpiochip_add_irqchip(struct gpio_chip *gc, > > > > return ret; > > > > } else { > > > > /* Some drivers provide custom irqdomain ops */ > > > > - if (gc->irq.domain_ops) > > > > - ops = gc->irq.domain_ops; > > > > - > > > > - if (!ops) > > > > - ops = &gpiochip_domain_ops; > > > > - gc->irq.domain = irq_domain_add_simple(np, > > > > - gc->ngpio, > > > > - gc->irq.first, > > > > - ops, gc); > > > > + ops = gc->irq.domain_ops ?: &gpiochip_domain_ops; > > > > + if (gc->irq.first) > > > > + gc->irq.domain = irq_domain_create_legacy(fwnode, gc->ngpio, > > > > + gc->irq.first, 0, > > > > + ops, gc); > > > > + else > > > > + gc->irq.domain = irq_domain_create_linear(fwnode, gc->ngpio, > > > > + ops, gc); > > > > > > This looks like a refactoring and reimplementation of irq_domain_add_simple()? > > > > If you named it as irq_domain_create_simple(), then yes, but the problem is > > that we don't have irq_domain_create_simple() API right now. > > > > > Why, and should it rather be a separate patch? > > > > Nope. > > OK I looked closer at irq_domain_add_simple(), and what it does different > is to call irq_alloc_descs() for all lines if using sparse IRQs and then > associate them. irq_domain_create_linear|legacy() does not allocate IRQ > descriptors because it assumes something like DT or ACPI will do that > on-demand when drivers request IRQs. > > This may be dangerous because some old platforms do not resolve IRQs > at runtime and you will get NULL pointer exceptions. > > We then need to make sure all callers do what is done in e.g. > drivers/gpio/gpio-omap.c in the #ifdef CONFIG_ARCH_OMAP1 clause: > they need to be augmented to call irq_alloc_descs() explicitly, > and I don't think all of them do it as nicely for us as OMAP1. > > I might be overly cautious though, however that is why this code > uses irq_domain_add_simple(), came in commit > commit 2854d167cc545d0642277bf8b77f972a91146fc6 Ah, thanks! I was puzzled how and why the approach above had been extended like now. This explains it. Okay, I will introduce irq_domain_create_simple(). -- With Best Regards, Andy Shevchenko