From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtprelay6.synopsys.com ([198.182.37.59]:50312 "EHLO smtprelay.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750735AbeDXRUH (ORCPT ); Tue, 24 Apr 2018 13:20:07 -0400 Subject: Re: [RFC 10/10] tools: PCI: Add MSI-X support To: Alan Douglas , "bhelgaas@google.com" , "lorenzo.pieralisi@arm.com" , "Joao.Pinto@synopsys.com" , "jingoohan1@gmail.com" , "kishon@ti.com" , "niklas.cassel@axis.com" , "jesper.nilsson@axis.com" Cc: "linux-pci@vger.kernel.org" , "linux-doc@vger.kernel.org" , "linux-kernel@vger.kernel.org" References: <9865822fb89ea84cb55fe93e151295afcd5c96b3.1523379766.git.gustavo.pimentel@synopsys.com> From: Gustavo Pimentel Message-ID: Date: Tue, 24 Apr 2018 18:18:55 +0100 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Sender: linux-pci-owner@vger.kernel.org List-ID: Hi Alan, On 24/04/2018 10:57, Alan Douglas wrote: > Hi Gustavo, > > On 10 April 2018 18:15, Gustavo Pimentel wrote: >> Adds MSI-X support to the pcitest tool and modified the pcitest.sh script to >> accomodate this new type of interruption test. >> >> Signed-off-by: Gustavo Pimentel >> --- >> include/uapi/linux/pcitest.h | 1 + >> tools/pci/pcitest.c | 18 +++++++++++++++++- >> tools/pci/pcitest.sh | 25 +++++++++++++++++++++++++ >> 3 files changed, 43 insertions(+), 1 deletion(-) > I found some possible problems when testing with the Cadence EP driver. The problem > is that pcitest uses the BARs for tests, but we also use one for the MSI-X tables > > In Cadence core the MSI-X table is in BAR0 by default, but this is configured to a size > of 0x80 in the test driver, since it is used as the test_reg_bar. So, I changed the > configuration to use BAR4 instead, which is configured to a size of 131072 > in pci-efp-test.c, and this gives me enough space. > > However, if I run the BAR tests in pcitest before running the MSI-X tests, the > MSI-X tests fail, since the BAR content is overwritten. It's not a problem with the > scenario in pcitest.sh, but it would be if the module wasn't re-loaded. > > So, wondering if we need to come up with some mechanism to specify that a specific > BAR will be used for MSI-X, and that its size and content shouldn't be modified by > pcitest? I see your point. I have bypassed the problem by doing the module load/unload (to avoid having to fight on multiple fronts). I like your suggestion. Maybe we could have a bool variable for each BARs that could be set to false if a resource have intent to use it. However this change must be accepted by Kishon. > > Regards, > Alan > Regards, Gustavo