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 16C9CECAAD8 for ; Wed, 14 Sep 2022 11:43:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229937AbiINLnT (ORCPT ); Wed, 14 Sep 2022 07:43:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56526 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229935AbiINLnQ (ORCPT ); Wed, 14 Sep 2022 07:43:16 -0400 Received: from mail-pl1-x631.google.com (mail-pl1-x631.google.com [IPv6:2607:f8b0:4864:20::631]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7592C7C75C for ; Wed, 14 Sep 2022 04:43:13 -0700 (PDT) Received: by mail-pl1-x631.google.com with SMTP id l10so14851030plb.10 for ; Wed, 14 Sep 2022 04:43:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=user-agent:in-reply-to:content-disposition:mime-version:references :message-id:subject:cc:to:from:date:from:to:cc:subject:date; bh=33idBYFCA209mbgtuNpDyXjAqmtZgCVjerVNq6pkJTs=; b=ZuHmndqGGf6u5UtuBXdG6ItHcfgAjQeE6DIp43ODmI7EjWPliHSd+pyB0lWdTcyatm 1sPPBaOTGgfHnQ0+ROLpnTXemAKr5LKup53Y3WrCkCR1eejjCMMzbBBDA0c1iHehULe8 km5w/Zh5A1bqcUqsEZ6CR6IvMLhRCrMz38DFT/r3HyChrlIWfDf7QxtBG3pxsUGBflhb j83caFqoD+02TvHlt3OUd9A22oWU4/vOcxiQGUDLVHvO5yvaoV4VeT4Ch2xKt3xfHsfo vIQH/+r+VitUurUsjV8D2JRNDbSfGbnLtD33CCRA7BrgXABYqzC0Ko9a/qNNap3rxumq aBGw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=user-agent:in-reply-to:content-disposition:mime-version:references :message-id:subject:cc:to:from:date:x-gm-message-state:from:to:cc :subject:date; bh=33idBYFCA209mbgtuNpDyXjAqmtZgCVjerVNq6pkJTs=; b=py/Ia3SJslvlq/3NRR9+4JIDvZz96SOLtI+u88icz6OFVqTfnISokmKWPrjXyizVLd 4bkb0FNjw/nVy23k1EYnsa0UeM23MEN82oePOCOAC1gLSny5CzWKjsifGLwRGgg4x87D Cnb7Z1J4k+m2zUlBKo/l3L2/eRmQQ8ZJx0UiPk9sjcmxtR9pV38aSoWguxjha2tsHr0n 44l83CeX5HbG+2FZrp4YGw1zj9ofN6eX3nd3WhfOpGfHQfBpu/cWNOOwZMgYbJ8tmKEF D/ZxPv5Sq+9QeJIK4ftjjTbp3Qwh5zpHvOWrJgjmXIhEWQlaZLn3GZHwAjVMR0s3nQWx dWuQ== X-Gm-Message-State: ACgBeo3IxUTcwx8VxG4xAslQ0vQBPXtLUvVdb48wmrJzicHlJANy/zIH FVW1g69MMrxYaOsRV9giFxuy X-Google-Smtp-Source: AA6agR5ag1zkX0H9iLQGM/1UA7/eYstPU3VbIihZ8yKHixMVvDVXrwladTODkw+IQ+rn+xFxZNnjcQ== X-Received: by 2002:a17:902:f395:b0:178:2f95:4d0b with SMTP id f21-20020a170902f39500b001782f954d0bmr14953759ple.106.1663155792863; Wed, 14 Sep 2022 04:43:12 -0700 (PDT) Received: from workstation ([117.202.184.122]) by smtp.gmail.com with ESMTPSA id k29-20020aa7973d000000b00537ff911a89sm9844460pfg.105.2022.09.14.04.43.07 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Wed, 14 Sep 2022 04:43:11 -0700 (PDT) Date: Wed, 14 Sep 2022 17:13:06 +0530 From: Manivannan Sadhasivam To: Jon Hunter Cc: Vidya Sagar , Bjorn Helgaas , jingoohan1@gmail.com, gustavo.pimentel@synopsys.com, lpieralisi@kernel.org, robh@kernel.org, kw@linux.com, bhelgaas@google.com, treding@nvidia.com, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, kthota@nvidia.com, mmaddireddy@nvidia.com, sagar.tv@gmail.com Subject: Re: [PATCH V1] PCI: dwc: Use dev_info for PCIe link down event logging Message-ID: <20220914114306.GG16459@workstation> References: <20220913200746.GA619956@bhelgaas> <20220914062411.GD16459@workstation> <29b39edd-10ab-b679-f270-67b0b406ca2f@nvidia.com> <20220914111857.GF16459@workstation> <5ffe3dfa-28a5-a5fc-0ae2-28927c39dc03@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5ffe3dfa-28a5-a5fc-0ae2-28927c39dc03@nvidia.com> User-Agent: Mutt/1.9.4 (2018-02-28) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Sep 14, 2022 at 12:25:51PM +0100, Jon Hunter wrote: > > On 14/09/2022 12:18, Manivannan Sadhasivam wrote: > > On Wed, Sep 14, 2022 at 04:32:10PM +0530, Vidya Sagar wrote: > > > Agree with Mani. > > > Not all form factors support PRSNT pin (Ex:- M.2 Key-M form factor) and even > > > if the slot form factor supports PRSNT, it is not mandatory to have a GPIO > > > routed to the PRSNT pin of the slot. > > > > Right. > > > > > Also, since these are development platforms, we wouldn't want to keep > > > changing a controller's status in the DT, instead want to know the device's > > > presence/absence (by way of link up) looking at the log. > > > In my honest opinion, I don't think the absence of a device in the slot > > > should be treated as an error. > > > > > > > As I mentioned earlier, timeout can happen due to an issue with PHY layer > > also. In those cases, "dev_err()" is relevant. > > > > And I also agree that absence of the device should not be treated as an > > error. But my question is, if you know that the slot is going to be > > empty always, why cannot you just disable it in dts? > > I really don't think that makes sense from a usability perspective. You want > to allow users to connect PCI cards and for them to work without having to > update the DTB. I have plenty of open PCI slots on my PC and I would be a > bit upset if someone told me I need to update the PC firmware each time I > wanted to use a new slot. > My question was, "do you think the slot is going to be empty always". This can happen with slots exposed through a connector (not a PCIe one) and users would plug in add-on cards for accessing the slots. In those cases, the add-on specific devicetree can enable the PCIe instance and use it. But from your reply, I can infer that the slot is exposed on a standard PCIe connector and users would connect a PCIe device any time. Anyway, I don't strongly object the change and leave it to the maintainers to decide. Thanks, Mani > Jon > > -- > nvpublic