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=-0.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 531B3C2D0EC for ; Sat, 11 Apr 2020 00:23:18 +0000 (UTC) Received: from silver.osuosl.org (smtp3.osuosl.org [140.211.166.136]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 10C8820936 for ; Sat, 11 Apr 2020 00:23:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="XoxhyoMh" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 10C8820936 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linux-kernel-mentees-bounces@lists.linuxfoundation.org Received: from localhost (localhost [127.0.0.1]) by silver.osuosl.org (Postfix) with ESMTP id DEFDD20491; Sat, 11 Apr 2020 00:23:17 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from silver.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id cLfxCRUv1VIo; Sat, 11 Apr 2020 00:23:17 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by silver.osuosl.org (Postfix) with ESMTP id 0B96520346; Sat, 11 Apr 2020 00:23:17 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id E45A3C089F; Sat, 11 Apr 2020 00:23:16 +0000 (UTC) Received: from hemlock.osuosl.org (smtp2.osuosl.org [140.211.166.133]) by lists.linuxfoundation.org (Postfix) with ESMTP id A104CC0177 for ; Sat, 11 Apr 2020 00:23:15 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by hemlock.osuosl.org (Postfix) with ESMTP id 9C6DA88002 for ; Sat, 11 Apr 2020 00:23:15 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from hemlock.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id ZkVfDDrWAWNl for ; Sat, 11 Apr 2020 00:23:12 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by hemlock.osuosl.org (Postfix) with ESMTPS id CEE3087FCC for ; Sat, 11 Apr 2020 00:23:12 +0000 (UTC) Received: from localhost (mobile-166-170-220-109.mycingular.net [166.170.220.109]) (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 D96FF20936; Sat, 11 Apr 2020 00:23:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586564592; bh=FARqdX+GaBf5FcPQFajNGokyR/e7xk3P4078Qxn1Q6U=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=XoxhyoMhIUqKBZBzaIQb+1KWVnZNlI4CfJgbia1WrhJVDAXvZe5C5NfBWBPUXeiPw d98Tl37TdeBia4O/DvR2XpZ1zzfT3XP8R507RUAIzokf/K0imEp9UOeF6lIT6cl1rD fdH5WiH3sy2czlT6kz8PHVEot7RO9UiTVF2ql9ao= Date: Fri, 10 Apr 2020 19:23:10 -0500 From: Bjorn Helgaas To: Vaibhav Gupta , rjw@rjwysocki.net Message-ID: <20200411002310.GA44923@google.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200410124418.34640-1-vaibhavgupta40@gmail.com> Cc: linux-kernel-mentees@lists.linuxfoundation.org Subject: Re: [Linux-kernel-mentees] [PATCH v1] ethernet: intel: e1000: Convert to dev_pm_ops X-BeenThere: linux-kernel-mentees@lists.linuxfoundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-kernel-mentees-bounces@lists.linuxfoundation.org Sender: "Linux-kernel-mentees" On Fri, Apr 10, 2020 at 06:14:19PM +0530, Vaibhav Gupta wrote: > Convert the legacy callback .suspend() and .resume() > to the generic ones. > drivers/net/ethernet/intel/e1000/e1000_main.c | 47 +++++-------------- > @@ -5068,12 +5065,6 @@ static int __e1000_shutdown(struct pci_dev *pdev, bool *enable_wake) > e1000_down(adapter); > } > > -#ifdef CONFIG_PM > - retval = pci_save_state(pdev); > - if (retval) > - return retval; > -#endif __e1000_shutdown() is used in both by both e1000_suspend() and e1000_shutdown(). Suspend is obviously for power management, but I don't understand the connection between shutdown and PM. Why would something in the shutdown path would depend on CONFIG_PM? If we're in the shutdown path, we're either going to power off the whole machine or reboot (or kexec a new kernel). In any event, I don't think the pci_save_state() is needed, so removing it shouldn't hurt shutdown. But I'm curious about this common idiom in e1000 and other network drivers: e1000_shutdown() { ... if (system_state == SYSTEM_POWER_OFF) { pci_wake_from_d3(pdev, wake); pci_set_power_state(pdev, PCI_D3hot); } } The pci_wake_from_d3() part sort of makes sense -- we want to configure the device for wake-on-lan. But all the drivers that do this are network drivers. USB, keyboard, etc drivers also need that functionality, but none of them use pci_wake_from_d3(). Why? And why do we need the pci_set_power_state()? Seems like if we're going to power off the whole machine we wouldn't need to set devices to D3hot. Almost all the pci_set_power_state(pdev, PCI_D3hot) calls are from legacy suspend functions (which makes sense to me) or network driver shutdown functions, and I don't understand why network drivers do this differently than others. Bjorn _______________________________________________ Linux-kernel-mentees mailing list Linux-kernel-mentees@lists.linuxfoundation.org https://lists.linuxfoundation.org/mailman/listinfo/linux-kernel-mentees