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 E26D5CCA47E for ; Tue, 28 Jun 2022 14:57:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347590AbiF1O51 (ORCPT ); Tue, 28 Jun 2022 10:57:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35000 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345186AbiF1O50 (ORCPT ); Tue, 28 Jun 2022 10:57:26 -0400 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A202A33885; Tue, 28 Jun 2022 07:57:24 -0700 (PDT) Received: from fraeml738-chm.china.huawei.com (unknown [172.18.147.201]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4LXSLd2Bkrz689F7; Tue, 28 Jun 2022 22:55:05 +0800 (CST) Received: from lhreml710-chm.china.huawei.com (10.201.108.61) by fraeml738-chm.china.huawei.com (10.206.15.219) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Tue, 28 Jun 2022 16:57:22 +0200 Received: from localhost (10.202.226.42) by lhreml710-chm.china.huawei.com (10.201.108.61) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Tue, 28 Jun 2022 15:57:21 +0100 Date: Tue, 28 Jun 2022 15:57:20 +0100 From: Jonathan Cameron To: CC: Dan Williams , Bjorn Helgaas , Ben Widawsky , Alison Schofield , Lukas Wunner , Vishal Verma , Dave Jiang , , , Subject: Re: [PATCH V12 8/9] cxl/port: Retry reading CDAT on failure Message-ID: <20220628155720.000034cb@Huawei.com> In-Reply-To: <20220628041527.742333-9-ira.weiny@intel.com> References: <20220628041527.742333-1-ira.weiny@intel.com> <20220628041527.742333-9-ira.weiny@intel.com> Organization: Huawei Technologies Research and Development (UK) Ltd. X-Mailer: Claws Mail 4.0.0 (GTK+ 3.24.29; i686-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.202.226.42] X-ClientProxiedBy: lhreml712-chm.china.huawei.com (10.201.108.63) To lhreml710-chm.china.huawei.com (10.201.108.61) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 27 Jun 2022 21:15:26 -0700 ira.weiny@intel.com wrote: > From: Ira Weiny > > The CDAT read may fail for a number of reasons but mainly it is possible > to get different parts of a valid state. The checksum in the CDAT table > protects against this. > > Now that the cdat data is validated, issue a retry if the CDAT read > fails. For now 5 retries are implemented. > > Reviewed-by: Ben Widawsky > Reviewed-by: Alison Schofield > Signed-off-by: Ira Weiny > > --- > Changes from V10 > Pick up review tag and fix commit message > > Changes from V9 > Alison Schofield/Davidlohr Bueso > Print debug on each iteration and error only after failure > > Changes from V8 > Move code to cxl/core/pci.c > > Changes from V6 > Move to pci.c > Fix retries count > Change to 5 retries > > Changes from V5: > New patch -- easy to push off or drop. > --- > drivers/cxl/core/pci.c | 41 ++++++++++++++++++++++++++++++----------- > 1 file changed, 30 insertions(+), 11 deletions(-) > > diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c > index 6d775cc3dca1..d7c2a415cc5f 100644 > --- a/drivers/cxl/core/pci.c > +++ b/drivers/cxl/core/pci.c > @@ -618,36 +618,30 @@ static int cxl_cdat_read_table(struct device *dev, > return rc; > } > > -/** > - * read_cdat_data - Read the CDAT data on this port > - * @port: Port to read data from > - * > - * This call will sleep waiting for responses from the DOE mailbox. > - */ > -void read_cdat_data(struct cxl_port *port) > +static int __read_cdat_data(struct cxl_port *port) > { > static struct pci_doe_mb *cdat_mb; > struct device *dev = &port->dev; > struct device *uport = port->uport; > size_t cdat_length; > - int ret; > + int ret = 0; Fairly sure there isn't a path in which ret isn't set... Mixing ret and rc is a bit inconsistent, maybe scrub patch set for one or the other. (My fault originally I think :) > > cdat_mb = find_cdat_mb(uport); > if (!cdat_mb) { > dev_dbg(dev, "No CDAT mailbox\n"); > - return; > + return -EIO; > } > > port->cdat_sup = true; > > if (cxl_cdat_get_length(dev, cdat_mb, &cdat_length)) { > dev_dbg(dev, "No CDAT length\n"); > - return; > + return -EIO; > } > > port->cdat.table = devm_kzalloc(dev, cdat_length, GFP_KERNEL); > if (!port->cdat.table) > - return; > + return -ENOMEM; > > port->cdat.length = cdat_length; > ret = cxl_cdat_read_table(dev, cdat_mb, &port->cdat); > @@ -658,5 +652,30 @@ void read_cdat_data(struct cxl_port *port) > port->cdat.length = 0; > dev_err(dev, "CDAT data read error\n"); > } > + > + return ret; > +} > + > +/** > + * read_cdat_data - Read the CDAT data on this port > + * @port: Port to read data from > + * > + * This call will sleep waiting for responses from the DOE mailbox. > + */ > +void read_cdat_data(struct cxl_port *port) > +{ > + int retries = 5; > + int rc; > + > + while (retries--) { > + rc = __read_cdat_data(port); > + if (!rc) > + return; > + dev_dbg(&port->dev, > + "CDAT data read error rc=%d (retries %d)\n", > + rc, retries); > + } > + dev_err(&port->dev, "CDAT data read failed after %d retries\n", > + retries); > } > EXPORT_SYMBOL_NS_GPL(read_cdat_data, CXL);