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=-9.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, 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 07A89C433E0 for ; Wed, 20 Jan 2021 11:02:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AAE1E22242 for ; Wed, 20 Jan 2021 11:02:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388324AbhATKyJ (ORCPT ); Wed, 20 Jan 2021 05:54:09 -0500 Received: from mail.kernel.org ([198.145.29.99]:49390 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730986AbhATKFK (ORCPT ); Wed, 20 Jan 2021 05:05:10 -0500 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 69F792332A; Wed, 20 Jan 2021 10:04:29 +0000 (UTC) Received: from disco-boy.misterjones.org ([51.254.78.96] helo=www.loen.fr) by disco-boy.misterjones.org with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.94) (envelope-from ) id 1l2ALi-008uyI-S0; Wed, 20 Jan 2021 10:04:27 +0000 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Wed, 20 Jan 2021 10:04:25 +0000 From: Marc Zyngier To: Geert Uytterhoeven Cc: Saravana Kannan , Greg Kroah-Hartman , Rob Herring , Frank Rowand , Kevin Hilman , Android Kernel Team , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , Linux Kernel Mailing List Subject: Re: [PATCH] of: property: Add device link support for interrupts In-Reply-To: References: <20201218210750.3455872-1-saravanak@google.com> User-Agent: Roundcube Webmail/1.4.10 Message-ID: <4360c54bccf9c5a34052d1ad2b7eb049@kernel.org> X-Sender: maz@kernel.org X-SA-Exim-Connect-IP: 51.254.78.96 X-SA-Exim-Rcpt-To: geert@linux-m68k.org, saravanak@google.com, gregkh@linuxfoundation.org, robh+dt@kernel.org, frowand.list@gmail.com, khilman@baylibre.com, kernel-team@android.com, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On 2021-01-20 09:53, Geert Uytterhoeven wrote: > Hi Saravana, > > On Fri, Dec 18, 2020 at 10:11 PM Saravana Kannan > wrote: >> Add support for creating device links out of interrupts property. >> >> Cc: Marc Zyngier >> Cc: Kevin Hilman >> Signed-off-by: Saravana Kannan > > Thanks for your patch! > > This does not seem to add all links. I see links being created to the > secondary interrupt controller (e61c0000 "renesas,irqc"), but not to > the primary interrupt controller (GIC) > > Which is good, as the GIC driver is not a platform_driver, and thus > creating links would break everything ;-) > > BTW, I'd _love_ the GIC driver to be a platform_driver, as the GIC is > part of a power/and or clock domain on Renesas SoCs... The trouble is that we need the GIC much earlier than the device model is available, because the timer needs to be available super early. This isn't specific to the GIC, by the way, but also to all root interrupt controllers that end-up controlling the per-CPU interrupts. If you try to relax this constraint, you'll end up observing some of the very weird dependencies between sysfs, sched, and the device model (I went there a few years back, wasted a week on it, did a reset --hard on the branch, and swore never to look at this again! ;-) But for a start, I'd like the ITS code to be turned into a platform driver, as this would potentially allow for the various domains to be instantiated dynamically. One day. M. -- Jazz is not dead. It just smells funny...