From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f177.google.com (mail-pl1-f177.google.com [209.85.214.177]) (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 C200A78289 for ; Tue, 21 May 2024 15:40:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.177 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716306053; cv=none; b=exO21BFQgIWVU40ALrQNlF7wxdFotV2B/RY32PzNq39hzX+SVls+0aoWuRSCZAakB98lHbTzwMjvv0jRwKKma/EuVlH/r/b1ZSP2gkSlXWX1Xo9XzW4YZjVO5UD8sa1n72pYGAdjEbiT/thYAAIOupL80wnjL+VbDiywwS+5XyU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716306053; c=relaxed/simple; bh=fh4ig79HR1T76cXxQIw68f9i8vKVHSI4DF+AT4HSAvk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ABZhyWjFJqXgEVW/01uPhW7ST9OQJKgUYBBGLbH5KLS+1SyqI4BDpje4rF5pKvCsFdkT0S87/A1lYrxeLPyncW0bzJxTuHXxhiLB3XOST4CZZ/bNG3KjggfLQ+6fXP1gHjL3xbjGk84v5SYpJfKxx5Xf4Xs6IFQBnQsBnBqGyO8= 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=NWV+HWXq; arc=none smtp.client-ip=209.85.214.177 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="NWV+HWXq" Received: by mail-pl1-f177.google.com with SMTP id d9443c01a7336-1ee12baa01cso2549355ad.0 for ; Tue, 21 May 2024 08:40:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1716306051; x=1716910851; 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=UnGp/6vXmo6P9YdxT3N0iSjGrqp9ypanfUO389parWM=; b=NWV+HWXq94Hj+BdKIWp9PHd4tTjRD70t1pB6UbfT3PTOI4rps3GseYiO7+Zcqgr4cN OEbkJHTTthWBTckgptIFGRxtO9gR5jh4QT45HiwpQGJkQXpjCmC0gBoj6MhBuVniGExW bvDh8BQjjiGWQtGSZwGBmQ5wSn9X4Wj29LZgPJcgHUowh3G244hmTvY4uWKPYLOGbW8F mxGPX+vgq8VTNsZJ/1p/k/rwWK/piFQCKbBr1BjsgfiZ/PgVT/PkiE3yyuzKfdZZ6Lf4 BMhP66IjIb9gsq0cNeHwJJlgpZWyBFoJHbUwQtdm10MjOgJslWhLaPjEXBSvatJHWOMx M8Yg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1716306051; x=1716910851; 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=UnGp/6vXmo6P9YdxT3N0iSjGrqp9ypanfUO389parWM=; b=Oj0LcRm3NOnQf12eqrAY27hRuPDY+2PQmUHVkFbV2xoZ7Q7J8kBzobunG6xe4oH7Ey PgEoY2BwlsXV9Dx5bjEMmUkzUU8efEqeoQOxJtaov1cfnbvxfSGlI2N5fsR74NvizDY3 W5UohQ3PLSMepLjxIGQGKUo0MfqNeLd8Z6jH7didf0R87swDp//tivwUktt8wlHQckmb OeDiZeqfwEqx+Omfzpz9k5Ygm1+ISU74yqSZ/1PH/RJN35PmAjS7Aurp6WS9vdw2w1nw ZzxaWtljveu1d/2ONeN19aHBGAFA/Bl91sEXq+slbA0eQcBunQm7p/NHsH7B70aPZl94 6zzA== X-Gm-Message-State: AOJu0YzG6O486L9cmkrUThVhqJ9ZkroGL8wrOIaFXBdpAyPkNVAfCgGD fj/gmHFYpA8qiChxUzKiiJMNnWXLm/eho8RTZpk/kzVwwLop6YdL73wTucHzsoaTqVBlb6YmvrM = X-Google-Smtp-Source: AGHT+IE9/qgHxCwJ5baP+tq0PBH7jNC0Om4uR0u7EW8DhYJ84nxKi+8zRggB20Mj87yIx2tNDjJ78Q== X-Received: by 2002:a17:902:ec81:b0:1f3:6b0:e64d with SMTP id d9443c01a7336-1f306b0ea4amr57996135ad.67.1716306050972; Tue, 21 May 2024 08:40:50 -0700 (PDT) Received: from thinkpad ([120.60.74.2]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-1f3083e6bb7sm27879935ad.164.2024.05.21.08.40.48 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 21 May 2024 08:40:50 -0700 (PDT) Date: Tue, 21 May 2024 21:10:36 +0530 From: Manivannan Sadhasivam To: rafael@kernel.org Cc: linux-pm@vger.kernel.org, "linux-pci@vger.kernel.org Bjorn Helgaas" , Krishna Chaitanya Chundru Subject: Re: Behavior of the PM framework w.r.t the parent-child relationship Message-ID: <20240521154036.GA59482@thinkpad> References: Precedence: bulk X-Mailing-List: linux-pm@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: + linux-pci On Mon, Apr 22, 2024 at 03:30:18PM +0530, Krishna Chaitanya Chundru wrote: > Hi Rafael, > > We are planning to add runtime PM support to the PCIe controller driver > and facing some issues with runtime PM. These are the details. > > PCIe controller is a parent of the PCIe bridge dev node and PCIe > endpoint driver as shown below > > PCIe controller(Top level parent & parent of host bridge) > | > v > PCIe Host bridge(Parent of PCI-PCI bridge driver) > | > v > PCI-PCI bridge(Parent of endpoint driver) > | > v > PCIe endpoint driver > > There is no driver associated with the PCIe Host bridge device node. > And the runtime pm for the bridge node is not enabled explicitly. > > we are seeing PCIe controller driver is getting runtime suspended even > when the PCI-PCI bridge and PCIe endpoint driver are active. > Our expectation is controller driver runtime suspend will be called only > when the child drivers went to the runtime suspend as the controller > is parent device. > > For the things to work properly we are calling pm_runtime_set_active() & > pm_runtime_enable() in [1] > > As bridge device node doesn't have driver associated and it is kind of > integrated with the controller, So we are expecting when the controller > driver enables its runtime pm it should enable the bridge runtime pm > also and vice versa. > > Can you please check this behavior and see if it is something which > needs to be fixed at the PM framework. > Hi Rafael, Gentle ping on this thread! - Mani -- மணிவண்ணன் சதாசிவம்