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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1BD19C19F21 for ; Wed, 27 Jul 2022 18:59:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232328AbiG0S7m (ORCPT ); Wed, 27 Jul 2022 14:59:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42566 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231271AbiG0S6u (ORCPT ); Wed, 27 Jul 2022 14:58:50 -0400 Received: from mail-yw1-x1135.google.com (mail-yw1-x1135.google.com [IPv6:2607:f8b0:4864:20::1135]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AC2966E2F9 for ; Wed, 27 Jul 2022 11:08:08 -0700 (PDT) Received: by mail-yw1-x1135.google.com with SMTP id 00721157ae682-31e47ac84daso184253417b3.0 for ; Wed, 27 Jul 2022 11:08:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=NMXcRI87yufdY6/XT5cLLLORQt3sxSxSpP/LTh5+LvM=; b=S+TOJiLqHXqCcXVfOGmduOCIM0kskUGMNI92Ai1NEPb0uxl8PI2/KmpWvLVjiD919D ZvZS4emRhEfkqWESzGR5OlA4oWesobF5FDdCT+pj3IUTAQvEbfG3bcxkh6iWymMF1RU+ tTN0RwcYj1C6I2G7aaAoMjgrPeFGRE3ffcUa7oMvXlq0nIpJh7SmEjEyb1XXB6pVt9xr pWhBykPSHwtd4h0Xq157RIzg6P7UY4aEAIHcCKecJU5iKJOzl4QL6m54x48zjZP/7V// S6xdyM+FN8dU9RizSaLb4lV8OS/TPMjkoHJKI1dY/+79Oc3l+B/7a6THeWohcl2Ww4M8 A9fw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=NMXcRI87yufdY6/XT5cLLLORQt3sxSxSpP/LTh5+LvM=; b=5JpYMyR1akM8/PF8Wr4ofwcSMVTVlZmPyVBqk267nsZ0a2h16tc39UwByN64NZXqUs 5xCwrZupVl1wzqN9c1UrSs/vG4mTehNWvmUaqnJGhZZOTBtH+JcbVbuuezoDCmwC8kwX AwleNrkiQTmwd0/uugE2X687TX/K+b/Jx08NmZG0ri9Ei2/I3oZB6pROQ7DOt2LYGegL VEiHOvrhbL4Q8Wz7Trg0wXJxalTeHHj1vgYrqytgtWcui8906encfAjhguztg3QsCXlC TuOyRdQ35ja/gMSOasDJlnY3d4tzivmjudGJloAzrQitDgkqXbY3LcqzDMN++A2j4Unv bsSg== X-Gm-Message-State: AJIora8kyzcLPyQGWo6+/pMk2O5DtVu2AGegcXn4Uxb+WhA5dYS3B/90 CZawooXUG1QOmtNQj7VPpwEiw5+o1hcJoUr1LJ85y1X8YEY= X-Google-Smtp-Source: AGRyM1uD7b1fr29udoQDI9d1E7IIKfgZyoN4ai5FBzz23w5LGSBRFo2LyXt+kDCYDfuXed2hJDzynnxut0qJtcvmw4c= X-Received: by 2002:a81:4807:0:b0:31e:7002:46cc with SMTP id v7-20020a814807000000b0031e700246ccmr20494789ywa.83.1658945287641; Wed, 27 Jul 2022 11:08:07 -0700 (PDT) MIME-Version: 1.0 References: <20220302211100.65264-1-paul.kocialkowski@bootlin.com> <20220302211100.65264-2-paul.kocialkowski@bootlin.com> <20220727120631.iefzititedahdsdt@houat> In-Reply-To: From: Saravana Kannan Date: Wed, 27 Jul 2022 11:07:31 -0700 Message-ID: Subject: Re: [PATCH RFC v3 1/8] of: Mark interconnects property supplier as optional To: Paul Kocialkowski Cc: Maxime Ripard , Rob Herring , devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-sunxi@lists.linux.dev, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, Chen-Yu Tsai , Jernej Skrabec , Samuel Holland , Michael Turquette , Stephen Boyd , Frank Rowand , Laurent Pinchart , Thomas Petazzoni Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jul 27, 2022 at 10:17 AM Paul Kocialkowski wrote: > > Hi, > > On Wed 27 Jul 22, 09:06, Saravana Kannan wrote: > > On Wed, Jul 27, 2022 at 5:06 AM Maxime Ripard wrote: > > > > > > Hi, > > > > > > On Mon, Mar 07, 2022 at 07:34:22PM -0800, Saravana Kannan wrote: > > > > On Mon, Mar 7, 2022 at 3:21 PM Rob Herring wrote: > > > > > > > > > > +Saravana > > > > > > > > > > On Wed, Mar 02, 2022 at 10:10:53PM +0100, Paul Kocialkowski wrote: > > > > > > In order to set their correct DMA address offset, some devices rely on > > > > > > the device-tree interconnects property which identifies an > > > > > > interconnect node that provides a dma-ranges property that can be used > > > > > > to set said offset. > > > > > > > > > > > > Since that logic is all handled by the generic openfirmware and driver > > > > > > code, the device-tree description could be enough to properly set > > > > > > the offset. > > > > > > > > > > > > However the interconnects property is currently not marked as > > > > > > optional, which implies that a driver for the corresponding node > > > > > > must be loaded as a requirement. When no such driver exists, this > > > > > > results in an endless EPROBE_DEFER which gets propagated to the > > > > > > calling driver. This ends up in the driver never loading. > > > > > > > > > > > > Marking the interconnects property as optional makes it possible > > > > > > to load the driver in that situation, since the EPROBE_DEFER return > > > > > > code will no longer be propagated to the driver. > > > > > > > > > > > > There might however be undesirable consequences with this change, > > > > > > which I do not fully grasp at this point. > > > > > > > > Temporary NACK till I get a bit more time to take a closer look. I > > > > really don't like the idea of making interconnects optional. IOMMUs > > > > and DMAs were exceptions. Also, we kinda discuss similar issues in > > > > LPC. We had some consensus on how to handle these and I noted them all > > > > down with a lot of details -- let me go take a look at those notes > > > > again and see if I can send a more generic patch. > > > > > > > > Paul, > > > > > > > > Can you point to the DTS (not DTSI) file that corresponds to this? > > > > Also, if it's a builtin kernel, I'd recommend setting > > > > deferred_probe_timeout=1 and that should take care of it too. > > > > > > For the record, I also encountered this today on next-20220726 with this > > > device: > > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/arm/boot/dts/sun5i.dtsi#n775 > > > > > > The driver won't probe without fw_devlink=off > > > > Really? I basically ended up doing what I mentioned in my original > > reply. next-20220726 should have my changes that'll make sure > > fw_devlink doesn't block any probe (it'll still try to create as many > > device links as possible) after 10s (default deferred probe timeout). > > Can you try to find more info on why it's not probing? > > /devices_deferred should give more details. > > By the way last time I checked the initial issue that I reported appeared to be > fixed by the patch (Extend deferred probe timeout on driver registration). Thanks for the confirmation. -Saravana