From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pg1-f179.google.com (mail-pg1-f179.google.com [209.85.215.179]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5133D4C61F for ; Tue, 27 Feb 2024 17:08:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.179 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709053731; cv=none; b=KzF5p0Mvjn8C6S/rcp8xmfYoPjKg+9D7mkhL9RNH5+viJ6Y5uiRfVEEovvkMoqjNZCqtB+blwK60yw97ZNr4MapJoc8VsjpIXfOFEkhuKs8UboZ2GP4cMvSOo11xv8S5MBBxGhYqd0Ds2Gy+Ane9yRlawgYZ9rgeuCKmSqQkGng= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709053731; c=relaxed/simple; bh=LyIC2a8YCi8H35J3OmUP2FanwA/jMrbgvLb5jpkEIFM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=BdH2Or2FQoovkqmysLcIXDLS234t4Fr2WL++hbjkH8GHd5gItHHYRdUZTYHtIBt7nMtN3BVbOLvK0yyJlR0koB9X/tNcRskClGkoz62gSDZJqiXZlSL7thvCmQbSeLwbc2YX74i9XIcoINquw0kw2CFxQQwuyq+3LsPJz7+z0Nw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linaro.org; spf=pass smtp.mailfrom=linaro.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b=OV1FbHlu; arc=none smtp.client-ip=209.85.215.179 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linaro.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linaro.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="OV1FbHlu" Received: by mail-pg1-f179.google.com with SMTP id 41be03b00d2f7-5dbcfa0eb5dso4150434a12.3 for ; Tue, 27 Feb 2024 09:08:50 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1709053729; x=1709658529; darn=vger.kernel.org; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date:from:to :cc:subject:date:message-id:reply-to; bh=lmc3sjc8em17oChCJSQpaOzbhd1qpZMy7Z0nwlTPyEc=; b=OV1FbHluXUQPzO7NWQ4faDtrR1AkKEeiRAfRi/Yoqt1b9ql8Ne85nQy1UPWVbl91lv AdZpy+i78t4JRIivHJDth32osYdT9Nv+OJ7DCro5zZFlHp0+9cj7raWYuD5wgfgW4w6B 0e5ONboExYxPEjlR//w5nvSveC7Nn1DlZBcu73j35kPznjlDSAu5ezY9HNxOp+P29rNZ Nw4Xm5SJTlxNtawSsP6ZJqqlclKODCgezbhSLwy/CEnSZxJO7H9yTNSFc9MsT9u0aOKB ONoyzPGs8Ab+kTrRnrbwdGLc3kT6/tVW4HnEcnKyN9I6le7xE6uGOAhxTdWi1xdDEChi bSFg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1709053729; x=1709658529; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=lmc3sjc8em17oChCJSQpaOzbhd1qpZMy7Z0nwlTPyEc=; b=A290LgtIlQvNl5UAeN6woCBlBhpBqf5xIo8qQMe6+4N3Robw1wf3Ms1cFN9W/9rxhs ZnY+YKaUPtRG3X5SBo7Z7zZW3QyoiAWM+xoTZieOspR0aL4maVa35EuwiSLOHHST8AwF l/Sjk8E1xgfem9i6iFVQR0wS0IUIP1IjSSX0PJ4XzZHgy6bQb6qyeV4N+u0t2O01/J6i +IKJTmEq3N4kqS1uxMB8DSXVOSK8LBVfA6qfGIHHJc/1QLLbT4IMgGZ+cyn5tMwJ5iBM Y2GbbAKuuHI99r2YNZ6rbOMtu1iO/ZN/7AKylVTIvf8CHX1m1AtUxrH0yuQnlCBnmSs5 A5dw== X-Forwarded-Encrypted: i=1; AJvYcCXyyKXy1nu/6LYYqdN5YeyAJgfy0WKdKUQKns+QEDnGOhXbkywzTzzG600mfSe43x/qqHs9F8gfa+2uweeBhtX/2kBOYuoJ0WVn X-Gm-Message-State: AOJu0YyBU7qtGs/hQRCALMHu+jv9LyhMdbbohrAZU18/owrpyrgtJuaw p8zKluxjQZXx5XQKN3bpwFKByNWI2CMZ/myCb8lH/3YfChGqkdIBsnm1IV43jg== X-Google-Smtp-Source: AGHT+IHfCTuVOr5Vdon+2BmyjsKL8DKicx4h9TEm+qIcTGywS1ZZGmFjLcn17HKfB8h/qvkApA/qPA== X-Received: by 2002:a17:902:6b49:b0:1d9:8832:f800 with SMTP id g9-20020a1709026b4900b001d98832f800mr9202931plt.8.1709053729485; Tue, 27 Feb 2024 09:08:49 -0800 (PST) Received: from thinkpad ([117.213.97.177]) by smtp.gmail.com with ESMTPSA id d1-20020a170902c18100b001c407fac227sm1765279pld.41.2024.02.27.09.08.44 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 27 Feb 2024 09:08:48 -0800 (PST) Date: Tue, 27 Feb 2024 22:38:40 +0530 From: Manivannan Sadhasivam To: Bjorn Helgaas Cc: Bjorn Helgaas , Bjorn Andersson , Konrad Dybcio , Lorenzo Pieralisi , Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= , Rob Herring , Lukas Wunner , Mika Westerberg , quic_krichai@quicinc.com, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org Subject: Re: [PATCH v3] PCI: Add D3 support for PCI bridges in DT based platforms Message-ID: <20240227170840.GR2587@thinkpad> References: <20240227073057.GF2587@thinkpad> <20240227162535.GA239073@bhelgaas> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20240227162535.GA239073@bhelgaas> On Tue, Feb 27, 2024 at 10:25:35AM -0600, Bjorn Helgaas wrote: [...] > > Ok, I got the issue. TBH, I added the device tree property based on > > the existing quirks for the ACPI devices. But none of the DT based > > platforms I'm aware of (even the legacy Qcom MSM8996 chipset > > released in early 2016) doesn't have any issue with D3hot. But I'm > > just nervous to assume it is the case for all the DT based platforms > > in the wild. > > > > But to proceed further, what is your preference? Should we ammend > > the DT property to make it explicit that the propery only focuses on > > the D3hot capability of the bridge and it works as per the spec > > (PMCSR) or bite the bullet and enable D3hot for all the non-ACPI > > platforms? > > > > We can add quirks for the bridges later on if we happen to receive > > any bug report. > > I would assume all devices support D3hot via PMCSR per spec. We can > add quirks if we discover something that doesn't. > When you say "all devices", are you referring to bridges in DT platforms or the bridges across all platforms? - Mani > If we add annotations that "this device works correctly", we're > digging a hole for ourselves because it's impossible to remove those > annotations and they complicate all future maintenance. > > Bjorn -- மணிவண்ணன் சதாசிவம்