From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 382C7606A319 for ; Wed, 21 Oct 2026 06:58:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=4dUY4lfx; dkim=pass (2048-bit key, unprotected) header.d=intel.com header.i=@intel.com header.a=rsa-sha256 header.s=Intel header.b=BaBI4sAY DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To: Content-Transfer-Encoding:Content-Type:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=4CoDiCaTJN+LFxlwyURPQlkHoXPhaz72iTcURzvPQHU=; b=4dUY4lfxVwnBTqqIQChlcp1uXO LDYGpMojQvIwrVz994YZuMhmQc/cyjAkNv3YM+KQn54exIK70J7hYYtEjBTcPhVqkeGx0eFF1qvto 42ZK/PAtDPV9svr0tsID4678RSx1Wpp3xONarOIjyrcbX4nQT/t6FWQAtJuCFznfc+3FgH5+QG14t CizIYpifqpw8JhsHswjZchWcBOuc9K7/qgyBik50EsAZY5/eA0NR5PP/zBe/vg1BysqTpZh3XqriH mJNRpEGIvsf0WDYVjvh1Nyq4e7sBPhEOPM7MQeoQGiZC5htqq1psqNWkbcLKR5br4zj8/Nq8Vs/VC ZRFeKM5A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1xJQHf-0000000BDaz-162O; Wed, 21 Oct 2026 06:58:47 +0000 Received: from mgamail.intel.com ([192.198.163.11]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1xJQHd-0000000BDaS-0EPW for linux-arm-kernel@lists.infradead.org; Wed, 21 Oct 2026 06:58:46 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1792565925; x=1824101925; h=date:from:to:cc:subject:message-id:references: mime-version:content-transfer-encoding:in-reply-to; bh=i07QuMRn/2JfcFy0JuCMmwxFwETBHdVXa2IAMSqe/48=; b=BaBI4sAY1b8+0VHfS1AaKcRupD4Vy421NmSSLRkYT6KbhzPqh/wq5fBT fw+r1oBnBlJ7y33Z/K6GN6AOcFL0zT0YTZ8TFok20cqvwM5MmRid50TR8 659pUy/GQUBVggZ+R5a9ZvuQdofiQ0LfYh3zkgf5qBmlug8mdWueRcBtO pRRz9tgKZdQ+eqTcuz05urdPdYjoaXXnOwqaQr40DTOZjisd51rUArUF0 u4fOILLNrvyDoFcVDLw94TZa4kkwZg4jvEuMqL/NXSxjWtkhXaoLjUHeR EtS5S8k4DGKJj4Y7VKV84m2tbE+1k6IS1wwWvRfRj0d08lMxWzf3nk75j A==; X-CSE-ConnectionGUID: egGSOjY7QQyXS0Yk2CcwFQ== X-CSE-MsgGUID: 3b2p7L80Qf6KZpdDKqDaPQ== X-IronPort-AV: E=McAfee;i="6800,10657,11941"; a="1184187" X-IronPort-AV: E=Sophos;i="6.27,169,1787036400"; d="scan'208";a="1184187" Received: from orviesa007.jf.intel.com ([10.64.159.147]) by fmvoesa105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Oct 2026 23:58:43 -0700 X-CSE-ConnectionGUID: S6AFesmrT1+KJSlx5aB2uw== X-CSE-MsgGUID: +peAPlOLSZe1ssAQhB/ynQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.27,169,1787036400"; d="scan'208";a="2933131" Received: from cpetruta-mobl1.ger.corp.intel.com (HELO localhost) ([10.245.245.24]) by smtpauth.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Oct 2026 23:58:35 -0700 Date: Wed, 21 Oct 2026 09:58:33 +0300 From: Andy Shevchenko To: Lorenzo Pieralisi Cc: "Rafael J. Wysocki (Intel)" , Robin Murphy , Mark Rutland , Marc Zyngier , Daniel Lezcano , Thomas Gleixner , Greg Kroah-Hartman , Danilo Krummrich , Hanjun Guo , Sudeep Holla , Wim Van Sebroeck , Guenter Roeck , Catalin Marinas , Will Deacon , Bartosz Golaszewski , linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, driver-core@lists.linux.dev, linux-watchdog@vger.kernel.org Subject: Re: [PATCH RFC 02/11] ACPI: Introduce irq_get() for static fwnodes Message-ID: References: X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Organization: Intel Finland Oy - BIC 0357606-4 - c/o Alberga Business Park, 6 krs, Bertel Jungin Aukio 5, 02600 Espoo X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20261020_235845_109897_00726D6B X-CRM114-Status: GOOD ( 41.99 ) X-Spam-Score: -4.5 (----) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" X-Spam-Status: No, score=-4.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_EF,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 On Tue, Oct 20, 2026 at 05:30:00PM +0200, Lorenzo Pieralisi wrote: > On Mon, Oct 19, 2026 at 08:05:50PM +0200, Rafael J. Wysocki (Intel) wrote: > > On Mon, Oct 19, 2026 at 12:34 PM Lorenzo Pieralisi > > wrote: [...] > > Basically, yes, the idea is to defer the creation of the platform > > device until the dependency is met. > > > > > till the dependencies are cleared but then, without a _CRS, where will > > > the consumer driver find the platform device resources ? > > > > Well, good question. > > > > > There are multiple facets in this issue and possibly some of them have > > > been already solved but I need to pull them together. > > > > > > > Note that the dependencies can be added to acpi_dep_list after > > > > creating a struct acpi_device with acpi_add_single_object() and > > > > acpi_scan_add_dep() is not really suitable for that, but it should be > > > > doable if the dependencies can be found. > > > > > > > > > I need to have a deeper look into this next week but I wanted to ask first > > > > > whether there was something I missed - most likely. > > > > > > > > Well, it is not really straightforward. > > > > > > Yes it is getting messy. This RFC, with all its flaws, does not transparently > > > prevents enumeration but rather relies on -EPROBE_DEFER to sort out > > > dependencies - though it does so by adding more stuff into ACPI static fwnode > > > that to be honest I'd rather see gone. > > > > I think what you need is a notification mechanism that will trigger > > when a specific device (enumerated via the ACPI Namespace) becomes > > operational. It doesn't look like any of the existing ones (platform > > device probe deferral or ACPI device dependencies tracking) is really > > suitable for your use case. > > Yes. It might just be a notification from ACPI core to say "the driver for > this ACPI device probed, go create platform devices that depends on it". > > We can check and track the dependency in code that does create those > devices today. > > I will think about this to see how bad this might look like. Don't we do something similar in drivers/acpi/x86/lpss.c? > > > > I'm still not sure why you can't represent all devices in the ACPI > > > > namespace in addition to describing some of them in static tables. I > > > > guess that would work for everybody, wouldn't it? > > > > > > That's a fair point - though then code will have to work with firmware > > > that does NOT explicitly require those devices in the namespace (ie: firmware > > > as it is specified _now_); it can turn out to be a mess even less > > > manageable than this discussion ;-) > > > > If it has to work under these conditions anyway, then adding stuff to > > the namespace is rather pointless. > > Yes that's the problem, reworking the code to make it work with namespace > devices is doable the issue is existing firmware and that we can't change it > (and we can't create it in the kernel either). -- With Best Regards, Andy Shevchenko