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=-8.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,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 7B4AAC433DB for ; Fri, 5 Feb 2021 10:24:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 21FB864E56 for ; Fri, 5 Feb 2021 10:24:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230296AbhBEKYD (ORCPT ); Fri, 5 Feb 2021 05:24:03 -0500 Received: from mail-ot1-f53.google.com ([209.85.210.53]:42929 "EHLO mail-ot1-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229609AbhBEKVT (ORCPT ); Fri, 5 Feb 2021 05:21:19 -0500 Received: by mail-ot1-f53.google.com with SMTP id f6so6371557ots.9; Fri, 05 Feb 2021 02:21:03 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=W3RF2C/PA6a6ba6a9kvICkFlC1q6hnsnECE3kSeEdlo=; b=HJFofwczRVQAvLnj9wcxvk5wu3JM879AeQV1XQ9cArUXMFMukGQYp1hALPhmM/XgeD heaw8uCO88gni6htNwpAxIrrW7oXGIEO1ts6lWx8MrHmpgIK1IHXYb8FKNjwtwoTUHyT b7u5dG3Dyy9DFSJu7lyHyRXGuN6U+PTNcFcTYeENGglMLWZWClryWV1e/Y8vtWNDVg6F t8S7MG0Sdf87srY44mb1YyX/p/+TS1/0ZDFhNQlKxRuo+GLhufRTwArRTTN66UpwPWUc z/MuOl2iB0Y0UJdGJoap+CPYf74g9OPJVAmf1FvRHuNwseMkNsKBGqkAhag1eyE2hinM PujA== X-Gm-Message-State: AOAM531Xi8g9KGTnREZahRG1aOKNm1SMlAlkDvlk9n0ECkpDfkNEh+3V 1/Lkip2NE1Xgnb3985VZ6HbYhK0ht7Jhm9WKGrw= X-Google-Smtp-Source: ABdhPJxaAzP865Vmnvr1fq9k8jVK1cEEm2Qir3RiFDzwCxIrZEbUN97VUFhB9QV4+y8tU2656HDzFkvuQjfME2sklqE= X-Received: by 2002:a9d:3604:: with SMTP id w4mr2857988otb.107.1612520437777; Fri, 05 Feb 2021 02:20:37 -0800 (PST) MIME-Version: 1.0 References: <20210121225712.1118239-1-saravanak@google.com> <20210121225712.1118239-3-saravanak@google.com> <9692dfc9-4c63-71c9-b52b-d0feba466695@samsung.com> <6b606a5d-0435-1e9d-ac61-a8dacf051067@samsung.com> In-Reply-To: From: Geert Uytterhoeven Date: Fri, 5 Feb 2021 11:20:26 +0100 Message-ID: Subject: Re: [PATCH v2 2/2] of: property: Add fw_devlink support for interrupts To: Saravana Kannan Cc: Marek Szyprowski , Rob Herring , Frank Rowand , Greg Kroah-Hartman , linux-tegra , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , LKML , Linus Walleij , Bartosz Golaszewski , Jon Hunter , Marc Zyngier , Kevin Hilman , Android Kernel Team , Rob Herring , Thierry Reding Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Saravana, On Fri, Feb 5, 2021 at 11:06 AM Saravana Kannan wrote: > On Fri, Feb 5, 2021 at 12:06 AM Geert Uytterhoeven wrote: > > On Fri, Feb 5, 2021 at 8:38 AM Marek Szyprowski > > wrote: > > > On 04.02.2021 22:31, Saravana Kannan wrote: > > > > On Thu, Feb 4, 2021 at 3:52 AM Marek Szyprowski > > > > wrote: > > > >> On 21.01.2021 23:57, Saravana Kannan wrote: > > > >>> This allows fw_devlink to create device links between consumers of an > > > >>> interrupt and the supplier of the interrupt. > > > >>> > > > >>> Cc: Marc Zyngier > > > >>> Cc: Kevin Hilman > > > >>> Cc: Greg Kroah-Hartman > > > >>> Reviewed-by: Rob Herring > > > >>> Reviewed-by: Thierry Reding > > > >>> Reviewed-by: Linus Walleij > > > >>> Signed-off-by: Saravana Kannan > > > >> This patch landed some time ago in linux-next as commit 4104ca776ba3 > > > >> ("of: property: Add fw_devlink support for interrupts"). It breaks MMC > > > >> host controller operation on ARM Juno R1 board (the mmci@50000 device > > > >> defined in arch/arm64/boot/dts/arm/juno-motherboard.dtsi). I didn't > > > > I grepped around and it looks like the final board file is this or > > > > whatever includes it? > > > > arch/arm64/boot/dts/arm/juno-base.dtsi > > > The final board file is arch/arm64/boot/dts/arm/juno-r1.dts > > > > This patch just finds the interrupt-parent and then tries to use that > > > > as a supplier if "interrupts" property is listed. But the only > > > > interrupt parent I can see is: > > > > gic: interrupt-controller@2c010000 { > > > > compatible = "arm,gic-400", "arm,cortex-a15-gic"; > > > > > > > > And the driver uses IRQCHIP_DECLARE() and hence should be pretty much > > > > a NOP since those suppliers are never devices and are ignored. > > > > $ git grep "arm,gic-400" -- drivers/ > > > > drivers/irqchip/irq-gic.c:IRQCHIP_DECLARE(gic_400, "arm,gic-400", gic_of_init); > > > > > > > > This doesn't make any sense. Am I looking at the right files? Am I > > > > missing something? > > > > > > Okay, I've added displaying a list of deferred devices when mounting > > > rootfs fails and got following items: > > > > > > Deferred devices: > > > 18000000.ethernet platform: probe deferral - supplier > > > bus@8000000:motherboard-bus not ready > > > 1c050000.mmci amba: probe deferral - supplier > > > bus@8000000:motherboard-bus not ready > > > 1c1d0000.gpio amba: probe deferral - supplier > > > bus@8000000:motherboard-bus not ready > > > 2b600000.iommu platform: probe deferral - wait for supplier > > > scpi-power-domains > > > 7ff50000.hdlcd platform: probe deferral - wait for supplier scpi-clk > > > 7ff60000.hdlcd platform: probe deferral - wait for supplier scpi-clk > > > 1c060000.kmi amba: probe deferral - supplier > > > bus@8000000:motherboard-bus not ready > > > 1c070000.kmi amba: probe deferral - supplier > > > bus@8000000:motherboard-bus not ready > > > 1c170000.rtc amba: probe deferral - supplier > > > bus@8000000:motherboard-bus not ready > > > 1c0f0000.wdt amba: probe deferral - supplier > > > bus@8000000:motherboard-bus not ready > > > gpio-keys > > > Kernel panic - not syncing: VFS: Unable to mount root fs on > > > unknown-block(0,0) > > > > > > I don't see the 'bus@8000000:motherboard-bus' on the deferred devices > > > list, so it looks that device core added a link to something that is not > > > a platform device... > > Probe deferred devices (even platform devices) not showing up in that > list is not unusual. That's because devices end up on that list only > after a driver for them is matched and then it fails. > > > Lemme guess: bus@8000000 is a simple bus, but it has an > > interrupt-map, and the devlink code doesn't follow the mapping? > > > > No, what's happening is that (and this is something I just learned) > that if a parent has an "#interrupt-cells" property, it becomes your > interrupt parent. In this case, the motherboard-bus (still a platform > device) is the parent, but it never probes (because it's simple-bus > and "arm,vexpress,v2p-p1"). But it becomes the interrupt parent. And > this mmci device is marked as a consumer of this bus (while still a > grand-child). Yeah, I'm working on patches (multiple rewrites) to take > care of cases like this. One more reason to scrap the different handling of "simple-bus" and "simple-pm-bus", and use drivers/bus/simple-pm-bus.c, which is a platform device driver, for both? (like I originally intended ;-) Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds