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 B9E3FC433EF for ; Wed, 13 Jul 2022 08:48:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235174AbiGMIsE (ORCPT ); Wed, 13 Jul 2022 04:48:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57226 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231410AbiGMIsD (ORCPT ); Wed, 13 Jul 2022 04:48:03 -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 1B6DECAF32 for ; Wed, 13 Jul 2022 01:48:02 -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 1oBY2F-0005W2-6u; Wed, 13 Jul 2022 10:47:55 +0200 Message-ID: <26d5e056c4b4779293b79012468f2ac821f4c06c.camel@pengutronix.de> Subject: Re: [PATCH v14 13/17] PCI: imx6: Reduce resume time by only starting link if it was up before suspend From: Lucas Stach To: Richard Zhu , bhelgaas@google.com, robh+dt@kernel.org, broonie@kernel.org, lorenzo.pieralisi@arm.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, 13 Jul 2022 10:47:54 +0200 In-Reply-To: <1656645935-1370-14-git-send-email-hongxing.zhu@nxp.com> References: <1656645935-1370-1-git-send-email-hongxing.zhu@nxp.com> <1656645935-1370-14-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 01.07.2022 um 11:25 +0800 schrieb Richard Zhu: > Because i.MX PCIe doesn't support hot-plug feature. In the link down > scenario, only start the PCIe link training in resume when the link is up > before system suspend to avoid the long latency in the link training > period. > > Signed-off-by: Richard Zhu > Signed-off-by: Bjorn Helgaas > --- > drivers/pci/controller/dwc/pci-imx6.c | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > > diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c > index e236f824c808..5a06fbca82d6 100644 > --- a/drivers/pci/controller/dwc/pci-imx6.c > +++ b/drivers/pci/controller/dwc/pci-imx6.c > @@ -67,6 +67,7 @@ struct imx6_pcie { > struct dw_pcie *pci; > int reset_gpio; > bool gpio_active_high; > + bool link_is_up; > struct clk *pcie_bus; > struct clk *pcie_phy; > struct clk *pcie_inbound_axi; > @@ -881,11 +882,13 @@ static int imx6_pcie_start_link(struct dw_pcie *pci) > dev_info(dev, "Link: Gen2 disabled\n"); > } > > + imx6_pcie->link_is_up = true; > tmp = dw_pcie_readw_dbi(pci, offset + PCI_EXP_LNKSTA); > dev_info(dev, "Link up, Gen%i\n", tmp & PCI_EXP_LNKSTA_CLS); > return 0; > > err_reset_phy: > + imx6_pcie->link_is_up = false; > 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)); > @@ -1032,9 +1035,8 @@ static int imx6_pcie_resume_noirq(struct device *dev) > return ret; > dw_pcie_setup_rc(pp); > > - ret = imx6_pcie_start_link(imx6_pcie->pci); > - if (ret < 0) > - dev_info(dev, "pcie link is down after resume.\n"); > + if (imx6_pcie->link_is_up) > + imx6_pcie_start_link(imx6_pcie->pci); While the change itself is correct, the removal of the return value check should be added to the previous patch, as that's the point where you change this function to always return 0, rendering this check pointless. Regards, Lucas > > return 0; > }