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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 E116EC3A589 for ; Thu, 15 Aug 2019 21:32:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B940D20644 for ; Thu, 15 Aug 2019 21:32:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730540AbfHOVc0 (ORCPT ); Thu, 15 Aug 2019 17:32:26 -0400 Received: from ale.deltatee.com ([207.54.116.67]:36732 "EHLO ale.deltatee.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730517AbfHOVcZ (ORCPT ); Thu, 15 Aug 2019 17:32:25 -0400 Received: from s0106ac1f6bb1ecac.cg.shawcable.net ([70.73.163.230] helo=[192.168.11.155]) by ale.deltatee.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.89) (envelope-from ) id 1hyNM3-0007aB-C8; Thu, 15 Aug 2019 15:32:21 -0600 To: Bart Van Assche , Bjorn Helgaas Cc: linux-pci@vger.kernel.org, Christoph Hellwig , Keith Busch References: <20190815212821.120929-1-bvanassche@acm.org> From: Logan Gunthorpe Message-ID: <3dc57299-199f-4583-9b66-748a6aec059f@deltatee.com> Date: Thu, 15 Aug 2019 15:32:15 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20190815212821.120929-1-bvanassche@acm.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-SA-Exim-Connect-IP: 70.73.163.230 X-SA-Exim-Rcpt-To: keith.busch@intel.com, hch@lst.de, linux-pci@vger.kernel.org, bhelgaas@google.com, bvanassche@acm.org X-SA-Exim-Mail-From: logang@deltatee.com Subject: Re: [PATCH] PCI/P2PDMA: Fix a source code comment X-SA-Exim-Version: 4.2.1 (built Tue, 02 Aug 2016 21:08:31 +0000) X-SA-Exim-Scanned: Yes (on ale.deltatee.com) Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On 2019-08-15 3:28 p.m., Bart Van Assche wrote: > Commit 52916982af48 ("PCI/P2PDMA: Support peer-to-peer memory"; v4.20) > introduced the following text: "there's no way to determine whether the > root complex supports forwarding between them." A later commit added a > whitelist check in the function that comment applies to. Update the > comment to reflect the addition of the whitelist check. Thanks for the vigilant patch, but I've already got a series[1] that cleans up most of these commits. It looks like this patch will conflict with that series. Logan [1] https://lore.kernel.org/linux-pci/20190812173048.9186-1-logang@deltatee.com/ > Cc: Logan Gunthorpe > Cc: Christoph Hellwig > Cc: Keith Busch > Signed-off-by: Bart Van Assche > --- > drivers/pci/p2pdma.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c > index 234476226529..f719adc2b826 100644 > --- a/drivers/pci/p2pdma.c > +++ b/drivers/pci/p2pdma.c > @@ -300,8 +300,8 @@ static bool root_complex_whitelist(struct pci_dev *dev) > * Any two devices that don't have a common upstream bridge will return -1. > * In this way devices on separate PCIe root ports will be rejected, which > * is what we want for peer-to-peer seeing each PCIe root port defines a > - * separate hierarchy domain and there's no way to determine whether the root > - * complex supports forwarding between them. > + * separate hierarchy domain and there's no way other than using a whitelist > + * to determine whether the root complex supports forwarding between them. > * > * In the case where two devices are connected to different PCIe switches, > * this function will still return a positive distance as long as both >