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=-3.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no 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 D5D37C433DB for ; Fri, 12 Feb 2021 08:16:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A286164E57 for ; Fri, 12 Feb 2021 08:16:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229617AbhBLIPx (ORCPT ); Fri, 12 Feb 2021 03:15:53 -0500 Received: from mail-oi1-f178.google.com ([209.85.167.178]:44012 "EHLO mail-oi1-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229608AbhBLIPx (ORCPT ); Fri, 12 Feb 2021 03:15:53 -0500 Received: by mail-oi1-f178.google.com with SMTP id d20so9151874oiw.10; Fri, 12 Feb 2021 00:15:36 -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=AUw6a0oNfUGx7sV9+BDmLKTx8i0omztJvVehVvMjp08=; b=qEjn8JdK1Eu6xmpC/dDmOyxGdCxYz6cG7isOBUjSog9jKu+/4yYVCZ7xTih0XFJacg sTWFGJGY2vwFMKVVL5ATbldDK+oNO3UpNFr57m7gX2mf9fBGSh7WdxOg731/NH6AthMg 3N30EUfAWh5PBWE5hrMQYA+BFR5Si++VoWdvw0PBrRErEvGh290RjPjJGVSzvbQzjV4U IwKA1MpiWRo2zeidP+Ryicv8TCYipar4Y+MHA4ZZGYXuqutU/IELofxpXsUSZSFm3T5Q mJifoUgXTNsZN4C1r04D7nY1/xh44XirHAh2BaO/Ku9ZsBqPxyWCN4uYAqS3OKRIpYJL NAVw== X-Gm-Message-State: AOAM533p/j7sNKmu7ry4URASVaHnkD0jijp0uE3V3TEz8lZtS6ropovO hohCXFxA7wtWCsdDDW654SS4Azsv9ly4c59CobE= X-Google-Smtp-Source: ABdhPJy6z32m+bzOluIHnLsLpN1EyV/5RCGuvrp+ntL/2TP7Vc/kZ3Ry6sT9BbR+1Sm0fMQkDE9ovvBYq5nqPtBHZk8= X-Received: by 2002:aca:d8c6:: with SMTP id p189mr1109394oig.54.1613117711336; Fri, 12 Feb 2021 00:15:11 -0800 (PST) MIME-Version: 1.0 References: <20210205222644.2357303-1-saravanak@google.com> In-Reply-To: From: Geert Uytterhoeven Date: Fri, 12 Feb 2021 09:14:59 +0100 Message-ID: Subject: Re: [PATCH v4 0/8] Make fw_devlink=on more forgiving To: Saravana Kannan Cc: Jonathan Corbet , Greg Kroah-Hartman , "Rafael J. Wysocki" , Kevin Hilman , Ulf Hansson , Len Brown , Len Brown , Pavel Machek , Michael Turquette , Stephen Boyd , Rob Herring , Frank Rowand , Marc Zyngier , Thomas Gleixner , "open list:DOCUMENTATION" , Linux Kernel Mailing List , Linux PM list , linux-clk , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , ACPI Devel Maling List , Marek Szyprowski , Android Kernel Team , Linux-Renesas Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org Hi Saravana, On Fri, Feb 12, 2021 at 4:00 AM Saravana Kannan wrote: > On Thu, Feb 11, 2021 at 5:00 AM Geert Uytterhoeven wrote: > > 1. R-Car Gen2 (Koelsch), R-Car Gen3 (Salvator-X(S), Ebisu). > > > > - Commit 2dfc564bda4a31bc ("soc: renesas: rcar-sysc: Mark device > > node OF_POPULATED after init") is no longer needed (but already > > queued for v5.12 anyway) > > Rob doesn't like the proliferation of OF_POPULATED and we don't need > it anymore, so maybe work it out with him? It's a balance between some > wasted memory (struct device(s)) vs not proliferating OF_POPULATED. Rob: should it be reverted? For v5.13? I guess other similar "fixes" went in in the mean time. > > - Some devices are reprobed, despite their drivers returning > > a real error code, and not -EPROBE_DEFER: > > Sorry, it's not obvious from the logs below where "reprobing" is > happening. Can you give more pointers please? My log was indeed not a full log, but just the reprobes happening. I'll send you a full log by private email. > Also, thinking more about this, the only way I could see this happen is: > 1. Device fails with error that's not -EPROBE_DEFER > 2. It somehow gets added to a device link (with AUTOPROBE_CONSUMER > flag) where it's a consumer. > 3. The supplier probes and the device gets added to the deferred probe > list again. > > But I can't see how this sequence can happen. Device links are created > only when a device is added. And is the supplier isn't added yet, the > consumer wouldn't have probed in the first place. The full log doesn't show any evidence of the device being added to a list in between the two probes. > Other than "annoying waste of time" is this causing any other problems? Probably not. But see below. > > - The PCI reprobing leads to a memory leak, for which I've sent a fix > > "[PATCH] PCI: Fix memory leak in pci_register_io_range()" > > https://lore.kernel.org/linux-pci/20210202100332.829047-1-geert+renesas@glider.be/ > > Wrt PCI reprobing, > 1. Is this PCI never expected to probe, but it's being reattempted > despite the NOT EPROBE_DEFER error? Or There is no PCIe card present, so the failure is expected. Later it is reprobed, which of course fails again. > 2. The PCI was deferred probe when it should have probed and then when > it's finally reattemped and it could succeed, we are hitting this mem > leak issue? I think the leak has always been there, but it was just exposed by this unneeded reprobe. I don't think a reprobe after that specific error path had ever happened before. > I'm basically trying to distinguish between "this stuff should never > be retried" vs "this/it's suppliers got probe deferred with > fw_devlink=on vs but didn't get probe deferred with > fw_devlink=permissive and that's causing issues" There should not be a probe deferral, as no -EPROBE_DEFER was returned. > > - I2C on R-Car Gen3 does not seem to use DMA, according to > > /sys/kernel/debug/dmaengine/summary: > > > > -dma4chan0 | e66d8000.i2c:tx > > -dma4chan1 | e66d8000.i2c:rx > > -dma5chan0 | e6510000.i2c:tx > > I think I need more context on the problem before I can try to fix it. > I'm also very unfamiliar with that file. With fw_devlink=permissive, > I2C was using DMA? If so, the next step is to see if the I2C relative > probe order with DMA is getting changed and if so, why. Yes, I plan to dig deeper to see what really happens... > > - On R-Mobile A1, I get a BUG and a memory leak: > > > > BUG: spinlock bad magic on CPU#0, swapper/1 > > Hmm... I looked at this in bits and pieces throughout the day. At > least spent an hour looking at this. This doesn't make a lot of sense > to me. I don't even touch anything in this code path AFAICT. Are > modules/kernel mixed up somehow? I need more info before I can help. > Does reverting my pm domain change make any difference (assume it > boots this far without it). I plan to dig deeper to see what really happens... 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