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 D8611C433EF for ; Tue, 28 Jun 2022 03:33:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243240AbiF1DdR (ORCPT ); Mon, 27 Jun 2022 23:33:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52610 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243224AbiF1DdP (ORCPT ); Mon, 27 Jun 2022 23:33:15 -0400 Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 13D0F19295; Mon, 27 Jun 2022 20:33:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1656387194; x=1687923194; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=RIjvKUR796IyUxJTtFj5FcgK1bph80T/8NgXlcqVZDs=; b=cqkhiDiaroMY14r2sNoG0OaoRhawsBoXAgkSrSuw8zzv2rcnjwlHC+Dl 2Shn0dG98cpPWdmbF4Ko7clBK2SSVpXVmROeFOcuuSUuEQ89GQSyjGHJU Cng8iq8gE3Yn41auc9+3CFo7/6XdHvH6PjxSN3LhIhCqYqpMKXdkQGVrI tIWdmsdZRmbU4OuboLcRk6LKH51SyW0fjQQkkCrz78qFMzMy2RThtxXrf efqf1fEbshD+S53/jC3EFo2Fv4ReXqFwWqleD+DCqNkNePGRKWYygDVok 9+MO+QkgrJx2JNjKBBxeAanX7N8nDZozS/MlH7qaVMqyQUgThcBR7vVqH Q==; X-IronPort-AV: E=McAfee;i="6400,9594,10391"; a="279168348" X-IronPort-AV: E=Sophos;i="5.92,227,1650956400"; d="scan'208";a="279168348" Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Jun 2022 20:33:13 -0700 X-IronPort-AV: E=Sophos;i="5.92,227,1650956400"; d="scan'208";a="767016640" Received: from alison-desk.jf.intel.com (HELO alison-desk) ([10.54.74.41]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Jun 2022 20:33:13 -0700 Date: Mon, 27 Jun 2022 20:32:29 -0700 From: Alison Schofield To: "Weiny, Ira" Cc: "Williams, Dan J" , Bjorn Helgaas , Jonathan Cameron , Ben Widawsky , "Verma, Vishal L" , "Jiang, Dave" , "linux-kernel@vger.kernel.org" , "linux-cxl@vger.kernel.org" , "linux-pci@vger.kernel.org" Subject: Re: [PATCH V11 7/8] cxl/port: Retry reading CDAT on failure Message-ID: <20220628033229.GA1575428@alison-desk> References: <20220610202259.3544623-1-ira.weiny@intel.com> <20220610202259.3544623-8-ira.weiny@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220610202259.3544623-8-ira.weiny@intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Fri, Jun 10, 2022 at 01:22:58PM -0700, Ira Weiny 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 > Signed-off-by: Ira Weiny > Reviewed-by: Alison Schofield > --- > 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 | 40 +++++++++++++++++++++++++++++++--------- > 1 file changed, 31 insertions(+), 9 deletions(-) > > diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c > index cb70287e2984..fd02bc7c0d97 100644 > --- a/drivers/cxl/core/pci.c > +++ b/drivers/cxl/core/pci.c > @@ -617,19 +617,13 @@ 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; > > /* > * Ensure a reference on the underlying uport device which has the > @@ -640,17 +634,21 @@ void read_cdat_data(struct cxl_port *port) > cdat_mb = find_cdat_mb(uport); > if (!cdat_mb) { > dev_dbg(dev, "No CDAT mailbox\n"); > + ret = -EIO; > goto out; > } > > if (cxl_cdat_get_length(dev, cdat_mb, &cdat_length)) { > dev_dbg(dev, "No CDAT length\n"); > + ret = -EIO; > goto out; > } > > port->cdat.table = devm_kzalloc(dev, cdat_length, GFP_KERNEL); > - if (!port->cdat.table) > + if (!port->cdat.table) { > + ret = -ENOMEM; > goto out; > + } > > port->cdat.length = cdat_length; > ret = cxl_cdat_read_table(dev, cdat_mb, &port->cdat); > @@ -664,5 +662,29 @@ void read_cdat_data(struct cxl_port *port) > > out: > put_device(uport); > + 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); > -- > 2.35.1 >