From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756074AbdLOUIM (ORCPT ); Fri, 15 Dec 2017 15:08:12 -0500 Received: from aserp2130.oracle.com ([141.146.126.79]:44467 "EHLO aserp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755650AbdLOUIJ (ORCPT ); Fri, 15 Dec 2017 15:08:09 -0500 Subject: Re: [Xen-devel] [PATCH V3 1/2] Drivers/PCI: Export pcie_has_flr() interface To: Bjorn Helgaas Cc: jgross@suse.com, Sinan Kaya , Srikanth Jampala , Herbert Xu , Satanand Burla , linux-pci@vger.kernel.org, Felix Manlunas , linux-kernel@vger.kernel.org, Derek Chickles , Christoph Hellwig , JBeulich@suse.com, Russell Currey , bhelgaas@google.com, xen-devel@lists.xenproject.org, boris.ostrovsky@Oracle.COM, Raghu Vatsavayi , roger.pau@citrix.com References: <20171207222145.9769-1-Govinda.Tatti@Oracle.COM> <20171207222145.9769-2-Govinda.Tatti@Oracle.COM> <20171208202424.GC12367@bhelgaas-glaptop.roam.corp.google.com> <426eeeab-0dcd-8de3-9c5f-a166acf2c130@Oracle.COM> <20171212005919.GB30595@bhelgaas-glaptop.roam.corp.google.com> <49956aaf-5fd5-939d-5fc7-231ffdb98b70@Oracle.COM> <20171213212420.GH30595@bhelgaas-glaptop.roam.corp.google.com> <20171215181801.GU30595@bhelgaas-glaptop.roam.corp.google.com> From: Govinda Tatti Organization: Oracle Corporation Message-ID: <0ff910b6-9007-40b3-8943-45339603e868@Oracle.COM> Date: Fri, 15 Dec 2017 14:01:57 -0600 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.5.0 MIME-Version: 1.0 In-Reply-To: <20171215181801.GU30595@bhelgaas-glaptop.roam.corp.google.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=8746 signatures=668648 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1711220000 definitions=main-1712150282 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Thanks Bjorn for your response. Please see below for my comments. >> So, we should consider one of these options. >> >> - set PCI_DEV_FLAGS_NO_FLR_RESET if it is not supported. >> - pcie_flr() should return if it is not supported >> >> If we modify pcie_flr() to return error codes, then we need to modify >> all existing modules that are calling this function. > Yes, of course. > >> Please let me know your preference, so that I can move accordingly. Thanks. > I think Christoph volunteered to do some restructuring, but I don't > know his timeframe. If you can, I would probably wait for that > because there's so much overlap here. OK. > > The other paths that use PCI_EXP_DEVCTL_BCR_FLR are definitely issues > and should be fixed, but again should wait for the revised pcie_flr() > interface. And if they're not actually required for your Xen issue, > they sound like "nice to have" cleanups that will not gate your Xen > fixes. I added this to my ever-growing list of cleanups to do. For now, I am planning to use existing pcie_flr() after checking FLR capability inside Xenpciback driver (like other existing pcie_flr() usage). We will switch to revised pcie_flr() once it is available. Cheers GOVINDA