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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B2537C433F5 for ; Tue, 12 Apr 2022 12:12:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231913AbiDLMOQ (ORCPT ); Tue, 12 Apr 2022 08:14:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42622 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1352892AbiDLMMe (ORCPT ); Tue, 12 Apr 2022 08:12:34 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 0801A84ECD for ; Tue, 12 Apr 2022 04:13:57 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id C7DCB1570; Tue, 12 Apr 2022 04:13:56 -0700 (PDT) Received: from lpieralisi (unknown [10.57.8.134]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 5DD5F3F5A1; Tue, 12 Apr 2022 04:13:55 -0700 (PDT) Date: Tue, 12 Apr 2022 12:14:01 +0100 From: Lorenzo Pieralisi To: Marek =?iso-8859-1?Q?Beh=FAn?= Cc: Bjorn Helgaas , Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= , Marc Zyngier , pali@kernel.org, linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Gregory CLEMENT , Miquel Raynal , rafael@kernel.org Subject: Re: [PATCH 16/18] PCI: aardvark: Add suspend to RAM support Message-ID: <20220412111401.GA20749@lpieralisi> References: <20220220193346.23789-1-kabel@kernel.org> <20220220193346.23789-17-kabel@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20220220193346.23789-17-kabel@kernel.org> User-Agent: Mutt/1.9.4 (2018-02-28) Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org [+Rafael] On Sun, Feb 20, 2022 at 08:33:44PM +0100, Marek Behún wrote: > From: Miquel Raynal > > Add suspend and resume callbacks. The priority of these are > "_noirq()", to workaround early access to the registers done by the > PCI core through the ->read()/->write() callbacks at resume time. This commit log should be rewritten to clarify it. IIUC, you are hooking up the _noirq() callbacks to take advantage of callbacks ordering rather than needing the IRQ disabled per-se. Thread here: https://lore.kernel.org/linux-pci/20220220193346.23789-17-kabel@kernel.org I'd ask Rafael please if this is common practice or a workaround and whether that's how it should be done. Thanks, Lorenzo > Signed-off-by: Miquel Raynal > Signed-off-by: Pali Rohár > Signed-off-by: Marek Behún > --- > drivers/pci/controller/pci-aardvark.c | 39 +++++++++++++++++++++++++++ > 1 file changed, 39 insertions(+) > > diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c > index 3b51f47abd72..8c9ac7766ac7 100644 > --- a/drivers/pci/controller/pci-aardvark.c > +++ b/drivers/pci/controller/pci-aardvark.c > @@ -1896,6 +1896,44 @@ static int advk_pcie_setup_phy(struct advk_pcie *pcie) > return ret; > } > > +static int __maybe_unused advk_pcie_suspend(struct device *dev) > +{ > + struct advk_pcie *pcie = dev_get_drvdata(dev); > + > + advk_pcie_disable_phy(pcie); > + > + clk_disable_unprepare(pcie->clk); > + > + return 0; > +} > + > +static int __maybe_unused advk_pcie_resume(struct device *dev) > +{ > + struct advk_pcie *pcie = dev_get_drvdata(dev); > + int ret; > + > + ret = clk_prepare_enable(pcie->clk); > + if (ret) > + return ret; > + > + ret = advk_pcie_enable_phy(pcie); > + if (ret) > + return ret; > + > + advk_pcie_setup_hw(pcie); > + > + return 0; > +} > + > +/* > + * The PCI core will try to reconfigure the bus quite early in the resume path. > + * We must use the _noirq() alternatives to ensure the controller is ready when > + * the core uses the ->read()/->write() callbacks. > + */ > +static const struct dev_pm_ops advk_pcie_dev_pm_ops = { > + SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(advk_pcie_suspend, advk_pcie_resume) > +}; > + > static int advk_pcie_probe(struct platform_device *pdev) > { > struct device *dev = &pdev->dev; > @@ -2171,6 +2209,7 @@ static struct platform_driver advk_pcie_driver = { > .driver = { > .name = "advk-pcie", > .of_match_table = advk_pcie_of_match_table, > + .pm = &advk_pcie_dev_pm_ops, > }, > .probe = advk_pcie_probe, > .remove = advk_pcie_remove, > -- > 2.34.1 >