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=-11.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS autolearn=ham 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 5A455C433DB for ; Fri, 26 Feb 2021 22:23:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1659464DBD for ; Fri, 26 Feb 2021 22:23:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229990AbhBZWXO (ORCPT ); Fri, 26 Feb 2021 17:23:14 -0500 Received: from mail.kernel.org ([198.145.29.99]:55520 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230165AbhBZWXJ (ORCPT ); Fri, 26 Feb 2021 17:23:09 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 05BF464EC4; Fri, 26 Feb 2021 22:22:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1614378148; bh=8s/XKXRb4CorJtfRkBsrGYYS9jN/xNVULVhEkfuwWoE=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=W3lg2uVmBFu70NeWztp1viDjVk/IuVnP4C15SR/psLdV6UvBIKHdNiDBrqlcnjMQ3 e1RVLRQQb4WWh6tBlgc9F0i8u17ywIrUly/IOBA42nqZSGQxVUFKhYULZfTy6o5mzb OLydfBuOyyDr01ofY+ZHRYUvZFDEt+629wKQotOJBKu+eA/JODLfa/LDtdNtFv0PWI uhNTvqjigLhg1RsoP1+rKPNgUZtzG3amjGloWYu5AdZSiRJCb1ullm1IOqcIVqnh1i amLsbzeAPG+hnXrOe2kjiK1fcVwUT8OuGQwvUPaOBEbgXE7I46Eueco4hXjzdVxiHA UMJIhe5ZSm41Q== Date: Fri, 26 Feb 2021 16:22:25 -0600 From: Bjorn Helgaas To: Loic Poulain Cc: Bjorn Helgaas , linux-pci@vger.kernel.org, Dave Airlie , "Rafael J. Wysocki" , Vaibhav Gupta , linux-pm@vger.kernel.org Subject: Re: PME while runtime suspend Message-ID: <20210226222225.GA164608@bjorn-Precision-5520> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org [+cc Rafael, Dave (author of 42eca2302146), Vaibhav, linux-pm] On Fri, Feb 26, 2021 at 11:37:12AM +0100, Loic Poulain wrote: > Hi Bjorn, > > Trying to support runtime suspend in a driver, which puts the device > in D3hot and wait either for host/driver initiated resume > (runtime_get), or device initiated resume (PME). > > But, given that old change: 42eca2302146 ("PCI: Don't touch card regs > after runtime suspend D3") > > PME that was enabled from pci_finish_runtime_suspend() is not enabled > anymore for almost all drivers in case of runtime-suspend. The only > way to enable this is by calling pci_wake_from_d3() from the PCI device > driver's runtime_suspend() callback, but this function fails if the > device wake_up is not enabled, which makes sense since it targets > system-wide sleep wake-up (and wake-up is user/distro policy). > > So is there a proper way to allow PME while the device is runtime > suspended, without having to tell the user to enabled 'unrelated' wake_up > capability? pci_pm_runtime_suspend() calls pci_finish_runtime_suspend(), which enables wake-up, unless "pci_dev->state_saved". IIUC we should be enabling wake-up unless the driver has called pci_save_state() itself. So I infer that your driver does call pci_save_state() and the PCI core does not enable wake-up. Right? Why does your driver call pci_save_state()? In most cases I don't think drivers should need to do that themselves because the PCI core will do it for them. E.g., see Vaibhav's recent eb6779d4c505 ("e1000: use generic power management") [1] Bjorn [1] https://git.kernel.org/linus/eb6779d4c505