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=-8.3 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=unavailable 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 CE8E0C35646 for ; Fri, 21 Feb 2020 14:16:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AF4BA206EF for ; Fri, 21 Feb 2020 14:16:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728425AbgBUOP7 (ORCPT ); Fri, 21 Feb 2020 09:15:59 -0500 Received: from foss.arm.com ([217.140.110.172]:40260 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728081AbgBUOP7 (ORCPT ); Fri, 21 Feb 2020 09:15:59 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 0766C1FB; Fri, 21 Feb 2020 06:15:59 -0800 (PST) Received: from e121166-lin.cambridge.arm.com (e121166-lin.cambridge.arm.com [10.1.196.255]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 575C73F703; Fri, 21 Feb 2020 06:15:58 -0800 (PST) Date: Fri, 21 Feb 2020 14:15:53 +0000 From: Lorenzo Pieralisi To: Kunihiko Hayashi , Kishon Vijay Abraham I Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH RESEND] PCI: endpoint: Fix clearing start entry in configfs Message-ID: <20200221141553.GA15440@e121166-lin.cambridge.arm.com> References: <1576844677-24933-1-git-send-email-hayashi.kunihiko@socionext.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1576844677-24933-1-git-send-email-hayashi.kunihiko@socionext.com> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Dec 20, 2019 at 09:24:37PM +0900, Kunihiko Hayashi wrote: > The value of 'start' entry is no change whenever writing 0 to configfs. > So the endpoint that stopped once can't restart. > > The following command lines are an example restarting endpoint and > reprogramming configurations after receiving bus-reset. > > echo 0 > controllers/66000000.pcie-ep/start > rm controllers/66000000.pcie-ep/func1 > ln -s functions/pci_epf_test/func1 controllers/66000000.pcie-ep/ > echo 1 > controllers/66000000.pcie-ep/start > > However, the first 'echo' can't set 0 to 'start', so the last 'echo' can't > restart endpoint. I think your description is not correct - pci_epc_group->start is just used to check if an endpoint has been started or not (in pci_epc_epf_unlink() and that's a WARN_ON) but nonetheless this looks like a bug and ought to be fixed. I need Kishon's ACK to proceed. Thanks, Lorenzo > Fixes: d74679911610 ("PCI: endpoint: Introduce configfs entry for configuring EP functions") > Cc: Kishon Vijay Abraham I > Signed-off-by: Kunihiko Hayashi > --- > drivers/pci/endpoint/pci-ep-cfs.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/pci/endpoint/pci-ep-cfs.c b/drivers/pci/endpoint/pci-ep-cfs.c > index d1288a0..4fead88 100644 > --- a/drivers/pci/endpoint/pci-ep-cfs.c > +++ b/drivers/pci/endpoint/pci-ep-cfs.c > @@ -58,6 +58,7 @@ static ssize_t pci_epc_start_store(struct config_item *item, const char *page, > > if (!start) { > pci_epc_stop(epc); > + epc_group->start = 0; > return len; > } > > -- > 2.7.4 >