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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_2 autolearn=no 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 06134C433DB for ; Tue, 29 Dec 2020 21:32:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D9861221F8 for ; Tue, 29 Dec 2020 21:32:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726168AbgL2Vcc (ORCPT ); Tue, 29 Dec 2020 16:32:32 -0500 Received: from relay1-d.mail.gandi.net ([217.70.183.193]:52571 "EHLO relay1-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726126AbgL2Vcc (ORCPT ); Tue, 29 Dec 2020 16:32:32 -0500 X-Originating-IP: 91.174.235.35 Received: from windsurf (unknown [91.174.235.35]) (Authenticated sender: thomas.petazzoni@bootlin.com) by relay1-d.mail.gandi.net (Postfix) with ESMTPSA id C8144240005; Tue, 29 Dec 2020 21:31:47 +0000 (UTC) Date: Tue, 29 Dec 2020 22:31:46 +0100 From: Thomas Petazzoni To: Nadeem Athani Cc: , , , , , , , , , mparab@cadence.com, pthombar@cadence.com, sjakhade@cadence.com Subject: Re: [PATCH v6 2/2] PCI: cadence: Retrain Link to work around Gen2 training defect. Message-ID: <20201229223146.3081aa50@windsurf> In-Reply-To: <20201228140510.14641-3-nadeem@cadence.com> References: <20201228140510.14641-1-nadeem@cadence.com> <20201228140510.14641-3-nadeem@cadence.com> Organization: Bootlin X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.32; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Mon, 28 Dec 2020 15:05:10 +0100 Nadeem Athani wrote: > +static void cdns_pcie_retrain(struct cdns_pcie *pcie) Shouldn't this propagate a return value ? > +{ > + u32 lnk_cap_sls, pcie_cap_off = CDNS_PCIE_RP_CAP_OFFSET; > + u16 lnk_stat, lnk_ctl; > + > + /* > + * Set retrain bit if current speed is 2.5 GB/s, > + * but the PCIe root port support is > 2.5 GB/s. > + */ > + > + lnk_cap_sls = cdns_pcie_readl(pcie, (CDNS_PCIE_RP_BASE + pcie_cap_off + > + PCI_EXP_LNKCAP)); > + if ((lnk_cap_sls & PCI_EXP_LNKCAP_SLS) <= PCI_EXP_LNKCAP_SLS_2_5GB) > + return; > + > + lnk_stat = cdns_pcie_rp_readw(pcie, pcie_cap_off + PCI_EXP_LNKSTA); > + if ((lnk_stat & PCI_EXP_LNKSTA_CLS) == PCI_EXP_LNKSTA_CLS_2_5GB) { > + lnk_ctl = cdns_pcie_rp_readw(pcie, > + pcie_cap_off + PCI_EXP_LNKCTL); > + lnk_ctl |= PCI_EXP_LNKCTL_RL; > + cdns_pcie_rp_writew(pcie, pcie_cap_off + PCI_EXP_LNKCTL, > + lnk_ctl); > + > + if (cdns_pcie_host_wait_for_link(pcie)) > + return; Here, shouldn't you return the status of cdns_pcie_host_wait_for_link(), to propagate whether the PCIe link indeed came up after the retrain ? Thomas -- Thomas Petazzoni, CTO, Bootlin Embedded Linux and Kernel engineering https://bootlin.com