From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753943AbdLMUsQ (ORCPT ); Wed, 13 Dec 2017 15:48:16 -0500 Received: from aserp2130.oracle.com ([141.146.126.79]:41924 "EHLO aserp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753658AbdLMUsN (ORCPT ); Wed, 13 Dec 2017 15:48:13 -0500 Subject: Re: [Xen-devel] [PATCH V3 1/2] Drivers/PCI: Export pcie_has_flr() interface To: Bjorn Helgaas Cc: jgross@suse.com, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, JBeulich@suse.com, bhelgaas@google.com, xen-devel@lists.xenproject.org, boris.ostrovsky@Oracle.COM, 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> From: Govinda Tatti Organization: Oracle Corporation Message-ID: <49956aaf-5fd5-939d-5fc7-231ffdb98b70@Oracle.COM> Date: Wed, 13 Dec 2017 14:46:57 -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: <20171212005919.GB30595@bhelgaas-glaptop.roam.corp.google.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=8743 signatures=668646 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-1712130285 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >>>> -static bool pcie_has_flr(struct pci_dev *dev) >>>> +bool pcie_has_flr(struct pci_dev *dev) >>>> { >>>> u32 cap; >>>> @@ -3882,6 +3882,7 @@ static bool pcie_has_flr(struct pci_dev *dev) >>>> pcie_capability_read_dword(dev, PCI_EXP_DEVCAP, &cap); >>>> return cap & PCI_EXP_DEVCAP_FLR; >>>> } >>>> +EXPORT_SYMBOL_GPL(pcie_has_flr); >>> I'd rather change pcie_flr() so you could *always* call it, and it >>> would return 0, -ENOTTY, or whatever, based on whether FLR is >>> supported. Is that feasible? >> Sure, I will add pcie_has_flr() logic inside pcie_flr() and return >> appropriate >> values as suggested by you. Do we still want to retain pcie_has_flr() and >> its usage inside pci.c?.Otherwise, I will remove it and do required cleanup. > If you can restructure the code and remove pcie_has_flr() while > retaining the existing behavior of its callers, that would be great. I checked the current usage of pcie_has_flr() and pcie_flr(). I have a couple of questions or need some clarification. 1. pcie_has_flr() usage inside pci_probe_reset_function().    This function is only calling pcie_has_flr() but not pcie_flr().    Rest of the code is trying to do specific type of reset except pcie_flr().         rc = pci_dev_specific_reset(dev, 1);         if (rc != -ENOTTY)                 return rc;         if (pcie_has_flr(dev))                 return 0;         rc = pci_af_flr(dev, 1);         if (rc != -ENOTTY)                 return rc;    In other-words, I can remove usage of pcie_has_flr() in all other places    in pci.c except in above function. 2. W.r.t pcie_flr(), I am planning to return error code. Currently, the following    file/modules are calling this function. My plan is to add a check for return    code and print a WANRING message if return code is NON-ZERO. I hope this is    sufficient for this patch.    drivers/crypto/qat/qat_common/adf_aer.c    drivers/infiniband/hw/hfi1/chip.c (2 places)    drivers/net/ethernet/cavium/liquidio/lio_vf_main.c    drivers/net/ethernet/intel/ixgbe/ixgbe_main.c (2 places)    drivers/pci/quirks.c (2 places) Cheers GOVINDA