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 143E2C433EF for ; Wed, 8 Jun 2022 08:05:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231555AbiFHIFu (ORCPT ); Wed, 8 Jun 2022 04:05:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53524 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231907AbiFHIFB (ORCPT ); Wed, 8 Jun 2022 04:05:01 -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 B74AF1F4D10 for ; Wed, 8 Jun 2022 00:35:22 -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 1nyqDj-0000W7-7k; Wed, 08 Jun 2022 09:35:15 +0200 Message-ID: <5be4f4322e00e33fa9417280b0d74ecb7aab913e.camel@pengutronix.de> Subject: Re: [PATCH v9 6/8] PCI: imx6: Disable clocks and regulators after link is down 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 09:35:14 +0200 In-Reply-To: <1651801629-30223-7-git-send-email-hongxing.zhu@nxp.com> References: <1651801629-30223-1-git-send-email-hongxing.zhu@nxp.com> <1651801629-30223-7-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: > Since i.MX PCIe doesn't support hot-plug, reduce power consumption > as much as possible by disabling clocks and regulators and returning > error when the link is down. > > Signed-off-by: Richard Zhu > --- > drivers/pci/controller/dwc/pci-imx6.c | 19 +++++++++++++++---- > 1 file changed, 15 insertions(+), 4 deletions(-) > > diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c > index 3ce3993d5797..d122c12193a6 100644 > --- a/drivers/pci/controller/dwc/pci-imx6.c > +++ b/drivers/pci/controller/dwc/pci-imx6.c > @@ -845,7 +845,9 @@ static int imx6_pcie_start_link(struct dw_pcie *pci) > /* Start LTSSM. */ > imx6_pcie_ltssm_enable(dev); > > - dw_pcie_wait_for_link(pci); > + ret = dw_pcie_wait_for_link(pci); > + if (ret) > + goto err_out; This adds back error handling that has been intentionally removed in f81f095e8771 ("PCI: imx6: Allow to probe when dw_pcie_wait_for_link() fails"). While I agree that disabling the clocks and regulators is the right thing to do when we don't manage to get a link, we should still allow the driver to probe, so please add a "ret = 0" to this newly added non-fatal error paths. > > if (pci->link_gen == 2) { > /* Allow Gen2 mode after the link is up. */ > @@ -876,12 +878,14 @@ static int imx6_pcie_start_link(struct dw_pcie *pci) > ret = imx6_pcie_wait_for_speed_change(imx6_pcie); > if (ret) { > dev_err(dev, "Failed to bring link up!\n"); > - goto err_reset_phy; > + goto err_out; > } > } > > /* Make sure link training is finished as well! */ > - dw_pcie_wait_for_link(pci); > + ret = dw_pcie_wait_for_link(pci); > + if (ret) > + goto err_out; > } else { > dev_info(dev, "Link: Gen2 disabled\n"); > } > @@ -890,11 +894,18 @@ static int imx6_pcie_start_link(struct dw_pcie *pci) > dev_info(dev, "Link up, Gen%i\n", tmp & PCI_EXP_LNKSTA_CLS); > return 0; > > -err_reset_phy: > +err_out: > dev_dbg(dev, "PHY DEBUG_R0=0x%08x DEBUG_R1=0x%08x\n", > dw_pcie_readl_dbi(pci, PCIE_PORT_DEBUG0), > dw_pcie_readl_dbi(pci, PCIE_PORT_DEBUG1)); > imx6_pcie_reset_phy(imx6_pcie); > + imx6_pcie_clk_disable(imx6_pcie); > + if (imx6_pcie->phy != NULL) { Please use the more common if (imx6_pcie->phy) here. Regards, Lucas > + phy_power_off(imx6_pcie->phy); > + phy_exit(imx6_pcie->phy); > + } > + if (imx6_pcie->vpcie) > + regulator_disable(imx6_pcie->vpcie); > return ret; > } >