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=-7.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 04461C3F2C6 for ; Tue, 3 Mar 2020 18:57:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D1C6920866 for ; Tue, 3 Mar 2020 18:57:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583261865; bh=dQmdXT8vCjPlLFUTkGXnb4FVu0PaJqE2zy/kHtpDd6o=; h=References:In-Reply-To:From:Date:Subject:To:Cc:List-ID:From; b=QH6MeVoy6pvyACOocsqFgceW0q8Ko96xpzzvbWDFNf4I2stdqqzwm0uyTHIfShyKV 3Y7OIeAXeYFy9XyEqJimiNiR9mPuFxA5RqM83Qp2IH7QnniFFO2pFISmSzvnPkIr0B lyZRNjuLwk/ov4EKHpZvXTxEcajVVZ8+0GfmBQTY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729871AbgCCS5p (ORCPT ); Tue, 3 Mar 2020 13:57:45 -0500 Received: from mail-ot1-f66.google.com ([209.85.210.66]:42935 "EHLO mail-ot1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726766AbgCCS5o (ORCPT ); Tue, 3 Mar 2020 13:57:44 -0500 Received: by mail-ot1-f66.google.com with SMTP id 66so4108636otd.9; Tue, 03 Mar 2020 10:57:43 -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=8+50iwvf4+BPG6fbK1bhnsWbshJjC8gjUIQgfu0Tu/c=; b=VPwG1w6Y3RwLAyhoUFaxn2nsDDxm3FYDNHzLELvaVAyPnVdsbsbz8NfICCacZ/Ec4l kx7D6XVOUnL3HM7McBsz42Bo4byLx2mtYjj4C/uPqM5kySpoBCSCmOj1xsIdqrhTLkK+ ZMxVvY0EJ6xAlpWIPDPRn03ES+0lWU4l8NqWfKq1dIxX7k45gGwh8z/fOG/PUH1dA/Im akQio/nh/3eFQbo6bn7ZdBzlXDBJ8veuCfCov8FtgmRQ3SC+1OfZQeo4GQf3JfYVAeKq +YIXZkV/XAois8ywr1JmBq0c4zF8StC58NjNbfOd5oYSSwWFfEtp+9ZE1/H/ci+jyNRz R0QA== X-Gm-Message-State: ANhLgQ1FlJrDVzwSpVwvvSx4zTNmDXZgTwobi9ImKDK+hub4bjrnvOKY Pe1qbW8sPBuNwmZfMm+3jEz0TvZ/XXQvhl4Ejzc= X-Google-Smtp-Source: ADFU+vs1JBo5ZgHvPapYTkntqLLq0Hjz1ls0WxGg/KjxAFJVv4Lvf+XSgXQWepTFh6rRzt+hV4o5zOrwBTSRyKFhju8= X-Received: by 2002:a9d:6b04:: with SMTP id g4mr4175051otp.167.1583261862784; Tue, 03 Mar 2020 10:57:42 -0800 (PST) MIME-Version: 1.0 References: <20200303132852.13184-1-stanspas@amazon.com> <20200303132852.13184-5-stanspas@amazon.com> In-Reply-To: <20200303132852.13184-5-stanspas@amazon.com> From: "Rafael J. Wysocki" Date: Tue, 3 Mar 2020 19:57:31 +0100 Message-ID: Subject: Re: [PATCH v3 04/17] PCI: Do not override delay for D0->D3hot transition To: Stanislav Spassov Cc: Linux PCI , Stanislav Spassov , ACPI Devel Maling List , Bjorn Helgaas , Thomas Gleixner , Andrew Morton , =?UTF-8?B?SmFuIEggLiBTY2jDtm5oZXJy?= , Jonathan Corbet , Ashok Raj , Alex Williamson , Sinan Kaya , Rajat Jain , kbuild test robot Content-Type: text/plain; charset="UTF-8" Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Tue, Mar 3, 2020 at 2:30 PM Stanislav Spassov wrote: > > From: Stanislav Spassov > > Both specifications that document mechanisms for overriding the > D3hot->D0 waiting time only speak of this specific direction. > Nothing is mentioned about the opposite (D*->D3hot) except for > the default value of 10ms in PCI Express Base Specification > r5.0 (May 22, 2019), Section 5.9 "State Transition Recovery Time > Requirements". Unless you have a specific example of a system on which the current code doesn't work (and which should be mentioned here), I don't think that it is a good idea to make this change. There are systems in which it would make a measurable difference in things like the time it takes to suspend the system. > Signed-off-by: Stanislav Spassov > --- > drivers/pci/pci.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > index c1a866f733e9..03103bb15b42 100644 > --- a/drivers/pci/pci.c > +++ b/drivers/pci/pci.c > @@ -4589,7 +4589,7 @@ static int pci_pm_reset(struct pci_dev *dev, int probe) > csr &= ~PCI_PM_CTRL_STATE_MASK; > csr |= PCI_D3hot; > pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, csr); > - pci_dev_d3_sleep(dev); > + msleep(PCI_PM_D3_WAIT); > > csr &= ~PCI_PM_CTRL_STATE_MASK; > csr |= PCI_D0; > -- > 2.25.1 > > > > > Amazon Development Center Germany GmbH > Krausenstr. 38 > 10117 Berlin > Geschaeftsfuehrung: Christian Schlaeger, Jonathan Weiss > Eingetragen am Amtsgericht Charlottenburg unter HRB 149173 B > Sitz: Berlin > Ust-ID: DE 289 237 879 > > >