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=-9.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 6F705C433E2 for ; Wed, 9 Sep 2020 16:21:07 +0000 (UTC) Received: from whitealder.osuosl.org (smtp1.osuosl.org [140.211.166.138]) (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 CE3BE206B8 for ; Wed, 9 Sep 2020 16:21:06 +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="mEkygTjN" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CE3BE206B8 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 whitealder.osuosl.org (Postfix) with ESMTP id 5B321872DA; Wed, 9 Sep 2020 16:21:06 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from whitealder.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id ePF5w5mWSSXx; Wed, 9 Sep 2020 16:21:05 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by whitealder.osuosl.org (Postfix) with ESMTP id A8BB4872ED; Wed, 9 Sep 2020 16:21:05 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 8FE41C0052; Wed, 9 Sep 2020 16:21:05 +0000 (UTC) Received: from hemlock.osuosl.org (smtp2.osuosl.org [140.211.166.133]) by lists.linuxfoundation.org (Postfix) with ESMTP id 3310DC0051 for ; Wed, 9 Sep 2020 16:21:04 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by hemlock.osuosl.org (Postfix) with ESMTP id 218F1874E6 for ; Wed, 9 Sep 2020 16:21:04 +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 8gWQyJ9nHd3f for ; Wed, 9 Sep 2020 16:21:02 +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 D3283874E3 for ; Wed, 9 Sep 2020 16:21:02 +0000 (UTC) Received: from localhost (52.sub-72-107-123.myvzw.com [72.107.123.52]) (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 22D772080A; Wed, 9 Sep 2020 16:21:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599668462; bh=Os+2kdLhlGFHuAXnIKwsp2QyzksMHbIGTch+A2L27SM=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=mEkygTjNd7rBZIkApJjkQzebC0q4p7/j8XjD7Oz/8yphQWjfrYdcPildXlFdwuqd4 oL0KUjTWyAQQJ82PUruCAV5s7rPcqIHxsIiTXhQVQDaIuklN13ZF9eSNYQeIARjBQm MXjs4Dxd07f/OOU2Vuu6Ofkc03QrZZN9Xzp7RyCQ= Date: Wed, 9 Sep 2020 11:21:00 -0500 From: Bjorn Helgaas To: Vaibhav Gupta Message-ID: <20200909162100.GA710627@bjorn-Precision-5520> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200909152058.GA14223@gmail.com> Cc: Don Brace , Vaibhav Gupta , Bjorn Helgaas , Hannes Reinecke , Bradley Grove , linux-scsi@vger.kernel.org, Sathya Prakash , esc.storagedev@microsemi.com, James Smart , Kashyap Desai , Jack Wang , linux-kernel-mentees@lists.linuxfoundation.org, Dick Kennedy , Suganath Prabu Subramani , "James E.J. Bottomley" , John Garry , Adam Radford , Adaptec OEM Raid Solutions , megaraidlinux.pdl@broadcom.com, Sreekanth Reddy , "Martin K. Petersen" , Shivasharan S , MPT-FusionLinux.pdl@broadcom.com, linux-kernel@vger.kernel.org, Sumit Saxena Subject: Re: [Linux-kernel-mentees] [PATCH v2 01/15] scsi: megaraid_sas: use generic power management 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 Wed, Sep 09, 2020 at 08:50:58PM +0530, Vaibhav Gupta wrote: > On Wed, Sep 09, 2020 at 08:23:32AM -0500, Bjorn Helgaas wrote: > > On Wed, Sep 09, 2020 at 03:33:15PM +0530, Vaibhav Gupta wrote: > > > On Tue, Sep 08, 2020 at 12:32:09PM -0500, Bjorn Helgaas wrote: > > > > On Mon, Jul 20, 2020 at 07:04:14PM +0530, Vaibhav Gupta wrote: > > > > > With legacy PM hooks, it was the responsibility of a driver to manage PCI > > > > > states and also the device's power state. The generic approach is to let > > > > > the PCI core handle the work. > > > > > > > > > > PCI core passes "struct device*" as an argument to the .suspend() and > > > > > .resume() callbacks. As the .suspend() work with "struct instance*", > > > > > extract it from "struct device*" using dev_get_drv_data(). > > > > > > > > > > Driver was also using PCI helper functions like pci_save/restore_state(), > > > > > pci_disable/enable_device(), pci_set_power_state() and pci_enable_wake(). > > > > > They should not be invoked by the driver. > > > > > > > > > > Compile-tested only. > > > > > > > > > > Signed-off-by: Vaibhav Gupta > > > > > --- > > > > > drivers/scsi/megaraid/megaraid_sas_base.c | 61 ++++++----------------- > > > > > 1 file changed, 16 insertions(+), 45 deletions(-) > > > > > > > > > > diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c b/drivers/scsi/megaraid/megaraid_sas_base.c > > > > > index 00668335c2af..4a6ee7778977 100644 > > > > > --- a/drivers/scsi/megaraid/megaraid_sas_base.c > > > > > +++ b/drivers/scsi/megaraid/megaraid_sas_base.c > > > > > @@ -7539,25 +7539,21 @@ static void megasas_shutdown_controller(struct megasas_instance *instance, > > > > > megasas_return_cmd(instance, cmd); > > > > > } > > > > > > > > > > -#ifdef CONFIG_PM > > > > > /** > > > > > * megasas_suspend - driver suspend entry point > > > > > - * @pdev: PCI device structure > > > > > - * @state: PCI power state to suspend routine > > > > > + * @dev: Device structure > > > > > */ > > > > > -static int > > > > > -megasas_suspend(struct pci_dev *pdev, pm_message_t state) > > > > > +static int __maybe_unused > > > > > +megasas_suspend(struct device *dev) > > > > > { > > > > > - struct megasas_instance *instance; > > > > > - > > > > > - instance = pci_get_drvdata(pdev); > > > > > + struct megasas_instance *instance = dev_get_drvdata(dev); > > > > > > > > > > if (!instance) > > > > > return 0; > > > > > > > > > > instance->unload = 1; > > > > > > > > > > - dev_info(&pdev->dev, "%s is called\n", __func__); > > > > > + dev_info(dev, "%s is called\n", __func__); > > > > > > > > > > /* Shutdown SR-IOV heartbeat timer */ > > > > > if (instance->requestorId && !instance->skip_heartbeat_timer_del) > > > > > @@ -7579,7 +7575,7 @@ megasas_suspend(struct pci_dev *pdev, pm_message_t state) > > > > > > > > > > tasklet_kill(&instance->isr_tasklet); > > > > > > > > > > - pci_set_drvdata(instance->pdev, instance); > > > > > + dev_set_drvdata(dev, instance); > > > > > > > > It *might* be correct to replace "instance->pdev" with "dev", but it's > > > > not obvious and deserves some explanation. It's true that you can > > > > replace &pdev->dev with dev, but I don't know anything about > > > > instance->dev. > > > > Sorry, I meant "instance->pdev" here. > > > > > > I don't think this change is actually necessary, is it? > > > > "instance->pdev" is still a pci_dev pointer, so pci_set_drvdata() > > > > should work fine. ... > > > > > > > There is no instance->dev . The 'dev' passed dev_set_drvdata() is > > > same &pdev->dev. > > > > Yes, it's true that "dev" here is the same as the "&pdev->dev" we had > > previously. But we passed "instance->pdev" (not "pdev") to > > pci_set_drvdata(). So the question is whether instance->pdev->dev == > > dev. > > > > They *might* be the same, but I don't think it's obvious. > > > Yes, they are same. > driver/pci/pci-driver.c : > 'dev' is passed as parameter to both pci_device_probe() and pci_pm_suspend() > From 'dev', pci_device_probe() extracts "struct pci_dev*" and passes it to the > probe callback of this driver. > > In the proble function - megasas_probe_one() > :7347 instance->pdev = pdev; > :7386 pci_set_drvdata(pdev, instance); > > The proble function is using "struct pci_dev*" variable "pdev" provided by core > and same we replaced &pdev->dev with "struct device *dev". > > So the instance->pdev->dev and 'dev' can only differ if 'dev' passed to > pci_device_probe() and pci_pm_suspend() are different. OK. I think this requires too much analysis for this particular patch, which is really about deprecating pci_driver.suspend and .resume. We want patches to be easily verifiable with a minimum of extra research. I would completely support a separate patch to clean this up, though. The *ideal* thing would be to get rid of the set_drvdata() completely from the suspend routine. Doing it in the probe routine should be enough. > > > The dev pointer used here, points to same value. > > > > > > pci_get_drvdata() and pci_set_drvdata() invoke dev_get_drvdata() and > > > dev_set_drvdata() respectively. And they do nothing else. Seems like > > > additional unnecessary function calls and operations. _______________________________________________ Linux-kernel-mentees mailing list Linux-kernel-mentees@lists.linuxfoundation.org https://lists.linuxfoundation.org/mailman/listinfo/linux-kernel-mentees