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 AC21CC43334 for ; Wed, 8 Jun 2022 07:58:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231946AbiFHH6X (ORCPT ); Wed, 8 Jun 2022 03:58:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46542 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231292AbiFHH6D (ORCPT ); Wed, 8 Jun 2022 03:58:03 -0400 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9B9A81E225B for ; Wed, 8 Jun 2022 00:27:08 -0700 (PDT) Received: from gallifrey.ext.pengutronix.de ([2001:67c:670:201:5054:ff:fe8d:eefb] helo=[IPv6:::1]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1nyq5j-0007gI-Ff; Wed, 08 Jun 2022 09:26:59 +0200 Message-ID: <2427cef355dc1b9d1667a2c80448d2e23b97c447.camel@pengutronix.de> Subject: Re: [PATCH v9 5/8] PCI: imx6: Refine the regulator usage From: Lucas Stach To: Richard Zhu , bhelgaas@google.com, robh+dt@kernel.org, broonie@kernel.org, lorenzo.pieralisi@arm.com, jingoohan1@gmail.com, festevam@gmail.com, francesco.dolcini@toradex.com Cc: linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kernel@pengutronix.de, linux-imx@nxp.com Date: Wed, 08 Jun 2022 09:26:58 +0200 In-Reply-To: <1651801629-30223-6-git-send-email-hongxing.zhu@nxp.com> References: <1651801629-30223-1-git-send-email-hongxing.zhu@nxp.com> <1651801629-30223-6-git-send-email-hongxing.zhu@nxp.com> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.40.4 (3.40.4-1.fc34) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-SA-Exim-Connect-IP: 2001:67c:670:201:5054:ff:fe8d:eefb X-SA-Exim-Mail-From: l.stach@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-pci@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Am Freitag, dem 06.05.2022 um 09:47 +0800 schrieb Richard Zhu: > The driver should undo any enables it did itself. The regulator disable > shouldn't be basing decisions on regulator_is_enabled(). > > To keep the balance of the regulator usage counter, disable the regulator > just behind of imx6_pcie_assert_core_reset() in resume and shutdown. > > Signed-off-by: Richard Zhu > --- > drivers/pci/controller/dwc/pci-imx6.c | 19 +++++++------------ > 1 file changed, 7 insertions(+), 12 deletions(-) > > diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c > index 7005a7910003..3ce3993d5797 100644 > --- a/drivers/pci/controller/dwc/pci-imx6.c > +++ b/drivers/pci/controller/dwc/pci-imx6.c > @@ -369,8 +369,6 @@ static int imx6_pcie_attach_pd(struct device *dev) > > static void imx6_pcie_assert_core_reset(struct imx6_pcie *imx6_pcie) > { > - struct device *dev = imx6_pcie->pci->dev; > - > switch (imx6_pcie->drvdata->variant) { > case IMX7D: > case IMX8MQ: > @@ -400,14 +398,6 @@ static void imx6_pcie_assert_core_reset(struct imx6_pcie *imx6_pcie) > IMX6Q_GPR1_PCIE_REF_CLK_EN, 0 << 16); > break; > } > - > - if (imx6_pcie->vpcie && regulator_is_enabled(imx6_pcie->vpcie) > 0) { > - int ret = regulator_disable(imx6_pcie->vpcie); > - > - if (ret) > - dev_err(dev, "failed to disable vpcie regulator: %d\n", > - ret); > - } > } > > static unsigned int imx6_pcie_grp_offset(const struct imx6_pcie *imx6_pcie) > @@ -580,7 +570,7 @@ static int imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie) > struct device *dev = pci->dev; > int ret, err; > > - if (imx6_pcie->vpcie && !regulator_is_enabled(imx6_pcie->vpcie)) { > + if (imx6_pcie->vpcie) { > ret = regulator_enable(imx6_pcie->vpcie); > if (ret) { > dev_err(dev, "failed to enable vpcie regulator: %d\n", > @@ -653,7 +643,7 @@ static int imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie) > return 0; > > err_clks: > - if (imx6_pcie->vpcie && regulator_is_enabled(imx6_pcie->vpcie) > 0) { > + if (imx6_pcie->vpcie) { > ret = regulator_disable(imx6_pcie->vpcie); > if (ret) > dev_err(dev, "failed to disable vpcie regulator: %d\n", > @@ -1026,6 +1016,9 @@ static int imx6_pcie_resume_noirq(struct device *dev) > return 0; > > imx6_pcie_assert_core_reset(imx6_pcie); > + if (imx6_pcie->vpcie) > + regulator_disable(imx6_pcie->vpcie); > + This one looks misplaced. Surely you want the regulator to be on when resuming the PCIe subsystem. Isn't this just papering over a wrong usage count here, because there is no regulator_disable in imx6_pcie_suspend_noirq, where I would expect this to happen? Regards, Lucas > imx6_pcie_init_phy(imx6_pcie); > imx6_pcie_deassert_core_reset(imx6_pcie); > dw_pcie_setup_rc(pp); > @@ -1259,6 +1252,8 @@ static void imx6_pcie_shutdown(struct platform_device *pdev) > > /* bring down link, so bootloader gets clean state in case of reboot */ > imx6_pcie_assert_core_reset(imx6_pcie); > + if (imx6_pcie->vpcie) > + regulator_disable(imx6_pcie->vpcie); > } > > static const struct imx6_pcie_drvdata drvdata[] = {