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=-5.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,FAKE_REPLY_C,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 0BC5EC47404 for ; Mon, 7 Oct 2019 22:34:40 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 D2630206C0 for ; Mon, 7 Oct 2019 22:34:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="QkNolZfQ"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="l+VHYoud" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D2630206C0 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:References: List-Owner; bh=nQepw/FDe0Fg1y4QjzP/0G0CrS7O+pmJqqxbsst1ZGo=; b=QkNolZfQ0Fa5/k teeIhBfy5M05hQw6gDXflED/Y2jMHef467uFUskm9AJ6z9efmCGFTaafnJN4ebOMjNisu/GAEAatF ZBzzpAdmAJi7dMa6/U2mNChoH2YKZMXSmCgj41nWTHWCDUglML3VyY44W9Sz8sx88f+0dTRtD9iMg e3S13YbhPlZMJeaW6PuSXNTkybq9VBJsFbrs3/aEsxf6eErcN7leXG6pv1/0j1LK5uNKYcHubjYn1 /OphsZeeKDCLNCYj/wIjbXowaL1vDP9q/cdgfJLJV2YF2AWN5c9PmqcHEKTPL2QmOoAuMun4cV1BN g35rqv0TWi/Mzr9S54pA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.2 #3 (Red Hat Linux)) id 1iHbaN-0007SX-BW; Mon, 07 Oct 2019 22:34:35 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.92.2 #3 (Red Hat Linux)) id 1iHbaJ-0007Rm-Rr for linux-nvme@lists.infradead.org; Mon, 07 Oct 2019 22:34:33 +0000 Received: from localhost (unknown [69.71.4.100]) (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 AFD78206C0; Mon, 7 Oct 2019 22:34:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570487670; bh=LGBSGuz5q9yo8hI9Okbu1av/OqHVYJvDjRBLyWdeHjQ=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=l+VHYoudpyoV9iaA3IzzJYmS6Xzj05+MpEYQxm0RayzX19zv2bvuOo1THZKU44DF0 +/RKCBHtGlDq0ii3iA7U7ajRxB4C4h0kF6M54zbmqTza1xkHLgFRZLMgxVEyQGgCe8 ErahbP+R9O9kkCL6iBNowjUgn9RLtJi/JXtbCF9A= Date: Mon, 7 Oct 2019 17:34:28 -0500 From: Bjorn Helgaas To: "Rafael J. Wysocki" Subject: Re: [PATCH v3 1/2] PCI: PCIe: ASPM: Introduce pcie_aspm_enabled() Message-ID: <20191007223428.GA72605@google.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1618955.HVa0YQSOW5@kreacher> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191007_153431_948438_164D396C X-CRM114-Status: GOOD ( 19.78 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Sagi Grimberg , Mario Limonciello , Linux PCI , Linux PM , Linux Kernel Mailing List , linux-nvme , Keith Busch , Kai-Heng Feng , Keith Busch , Rajat Jain , Christoph Hellwig , Heiner Kallweit Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org [+cc Heiner] On Thu, Aug 08, 2019 at 11:55:07PM +0200, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki > > Add a function checking whether or not PCIe ASPM has been enabled for > a given device. > > It will be used by the NVMe driver to decide how to handle the > device during system suspend. > > Signed-off-by: Rafael J. Wysocki > --- > > v2 -> v3: > * Make the new function return bool. > * Change its name back to pcie_aspm_enabled(). > * Fix kerneldoc comment formatting. > > -> v2: > * Move the PCI/PCIe ASPM changes to a separate patch. > * Add the _mask suffix to the new function name. > * Add EXPORT_SYMBOL_GPL() to the new function. > * Avoid adding an unnecessary blank line. > > --- > drivers/pci/pcie/aspm.c | 20 ++++++++++++++++++++ > include/linux/pci.h | 3 +++ > 2 files changed, 23 insertions(+) > > Index: linux-pm/drivers/pci/pcie/aspm.c > =================================================================== > --- linux-pm.orig/drivers/pci/pcie/aspm.c > +++ linux-pm/drivers/pci/pcie/aspm.c > @@ -1170,6 +1170,26 @@ static int pcie_aspm_get_policy(char *bu > module_param_call(policy, pcie_aspm_set_policy, pcie_aspm_get_policy, > NULL, 0644); > > +/** > + * pcie_aspm_enabled - Check if PCIe ASPM has been enabled for a device. > + * @pci_device: Target device. > + */ > +bool pcie_aspm_enabled(struct pci_dev *pci_device) > +{ > + struct pci_dev *bridge = pci_upstream_bridge(pci_device); > + bool ret; > + > + if (!bridge) > + return false; > + > + mutex_lock(&aspm_lock); > + ret = bridge->link_state ? !!bridge->link_state->aspm_enabled : false; > + mutex_unlock(&aspm_lock); Why do we need to acquire aspm_lock here? We aren't modifying anything, and I don't think we're preventing a race. If this races with another thread that changes aspm_enabled, we'll return either the old state or the new one, and I think that's still the case even if we don't acquire aspm_lock. > + return ret; > +} > +EXPORT_SYMBOL_GPL(pcie_aspm_enabled); > + > #ifdef CONFIG_PCIEASPM_DEBUG > static ssize_t link_state_show(struct device *dev, > struct device_attribute *attr, > Index: linux-pm/include/linux/pci.h > =================================================================== > --- linux-pm.orig/include/linux/pci.h > +++ linux-pm/include/linux/pci.h > @@ -1567,8 +1567,11 @@ extern bool pcie_ports_native; > > #ifdef CONFIG_PCIEASPM > bool pcie_aspm_support_enabled(void); > +bool pcie_aspm_enabled(struct pci_dev *pci_device); > #else > static inline bool pcie_aspm_support_enabled(void) { return false; } > +static inline bool pcie_aspm_enabled(struct pci_dev *pci_device) > +{ return false; } > #endif > > #ifdef CONFIG_PCIEAER > > > _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme