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=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 A6581C54FD0 for ; Thu, 23 Apr 2020 20:14:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7EE3720724 for ; Thu, 23 Apr 2020 20:14:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587672866; bh=gHHCkAwFxNQxXMQq5clMRrI1sa3c+eHSB43jx6/M8Yc=; h=Date:From:To:Cc:Subject:In-Reply-To:List-ID:From; b=PzNK/1fBHgokH5v37sHDNaid1LWrxTDbHIaqvLXg6p+L0wXWJj4bkIdEFLcfhuBIR eNsF6U2CzLVmDZXuOBEIt9LX9NV1ZTWHhNI84k143zxAFxahXAEQWdD+B9t91YGacD rXnQDnDUSz7b6XI80lXDaM3QVSuf9zWi0w47++Oc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725884AbgDWUO0 (ORCPT ); Thu, 23 Apr 2020 16:14:26 -0400 Received: from mail.kernel.org ([198.145.29.99]:34472 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725877AbgDWUOZ (ORCPT ); Thu, 23 Apr 2020 16:14:25 -0400 Received: from localhost (mobile-166-175-187-210.mycingular.net [166.175.187.210]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 2A3AF20724; Thu, 23 Apr 2020 20:14:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587672865; bh=gHHCkAwFxNQxXMQq5clMRrI1sa3c+eHSB43jx6/M8Yc=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=WXKXi5ZzTrM2fCWgu0fp1glmjhg5gDEZ1G/R0bA6+O8gtfHnz7OGH1KSWSrT6s71K K8WHrWlOjCtg6duiRVmOOfci2RJnWKh7sTomUotAlt2OBEhdiBIgwtnSo/5qt7hBrP aSePLum/EKTQdd71r6Knayfh3jn0PkohSGeuzsQw= Date: Thu, 23 Apr 2020 15:14:23 -0500 From: Bjorn Helgaas To: Alex Deucher Cc: Linux PM , Linux PCI , "Rafael J. Wysocki" Subject: Re: runtime pm without pci or platform subsystem involvement Message-ID: <20200423201423.GA219985@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org On Thu, Apr 23, 2020 at 03:52:17PM -0400, Alex Deucher wrote: > On Wed, Apr 1, 2020 at 10:54 AM Alex Deucher wrote: > > I would like to be able to use the runtime pm infrastructure to > > support additional power savings at runtime for a PCIe device, but for > > various reasons, I need to keep the device in D0. I don't want the > > PCI or platform subsystem to put the device into D3hot/cold. Is this > > possible? If so how? I'd like to avoid spinning my own variant of > > runtime pm just to support this feature. If you clear pdev->pm_cap as in 434fdb51513b ("drm/nouveau: workaround runpm fail by disabling PCI power management on certain intel bridges"), we'll assume the device doesn't support any PCI power management, which means the PCI core should leave the device in D0. D3cold is handled by ACPI or other platform means. I don't know how to disable that part. Bjorn