Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Fri, 2 Jun 2023 13:16:28 +0300
From:   Vladimir Oltean <vladimir.oltean@nxp.com>
To:     Jianmin Lv <lvjianmin@loongson.cn>
Cc:     Liu Peibao <liupeibao@loongson.cn>,
        Bjorn Helgaas <helgaas@kernel.org>, linux-pci@vger.kernel.org,
        netdev@vger.kernel.org, Bjorn Helgaas <bhelgaas@google.com>,
        Rob Herring <robh@kernel.org>,
        Claudiu Manoil <claudiu.manoil@nxp.com>,
        Michael Walle <michael@walle.cc>, linux-kernel@vger.kernel.org,
        Binbin Zhou <zhoubinbin@loongson.cn>,
        Huacai Chen <chenhuacai@loongson.cn>
Subject: Re: [PATCH pci] PCI: don't skip probing entire device if first fn OF
 node has status = "disabled"
Message-ID: <20230602101628.jkgq3cmwccgsfb4c@skbuf>
References: <20230601163335.6zw4ojbqxz2ws6vx@skbuf>
 <ZHjaq+TDW/RFcoxW@bhelgaas>
 <20230601221532.2rfcda4sg5nl7pzp@skbuf>
 <dc430271-8511-e6e4-041b-ede197e7665d@loongson.cn>
 <7a7f78ae-7fd8-b68d-691c-609a38ab3161@loongson.cn>
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <7a7f78ae-7fd8-b68d-691c-609a38ab3161@loongson.cn>
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?c0VIZVlFdjBqbGwxWGZPT3BrLzdLbjJTRHJmeU1YNFdCV3dEZTYzOWZFNDFG?=
 =?utf-8?B?cUpUc09VVlRlZHlJSEJSQ0w3OHRXNzdsdVY2MjY5eWZVUTlpbG52Vk9tcmRk?=
 =?utf-8?B?RUlmYndaZ2t1S3Mzckw5UnBZbnM3d2ZoRXVXdjlKK1dsQ0ZxMVZCeS9uMFpu?=
 =?utf-8?B?YlN3aXZPaXhUQ0NDYkdjYndXM0l1NnVsOW44b3JDUE1UOThRV0djeGVMUkVI?=
 =?utf-8?B?eGoreiszclU3Nk90Zm11UzkzdG9GTnZ3SlZNaG12S1BOS1M1cEhCRlVHalJs?=
 =?utf-8?B?bWZTWGVFWUx6N01Eek9OOG5valJjeFRYMzVvam11ZEVIb0lJRUhHN0lTNmV0?=
 =?utf-8?B?a0xpODB6TE01MzBsSjRDcmNPTFZwazhrVVV4bk5UQ29qL0ptMmNpY2pkMFFl?=
 =?utf-8?B?RzhnL0pwdXRkVFBzaU04cVFYbnR3NHNzdUhjazR0cUtwamkxUnM2SXhubHZM?=
 =?utf-8?B?M2JmVURBSzJNUlJTSlBkNG5VZTljdnBEUFhrWjFFTUswT3FBQUlLTUZTTEQr?=
 =?utf-8?B?dXZuQmRJYlF0QkFobk5ET2tuWGMvVG1CZkJSVHM5UHZ2TXhOMXQ3U3AwZDJV?=
 =?utf-8?B?Z3lnLzU3Mk1kQ21mM1BhWExXMXVaVXNOUlA3NmhHSDdQa3hqcFpwRzMxemN5?=
 =?utf-8?B?SUtvUXZ4WEVCZWI2Rk1QUlRlS0YwRXlSb0JjYnhiMkRBMGhReDVLYVNoVHcz?=
 =?utf-8?B?K3IzdkRQYk1Ud0ZjRHJ6aEpySTMvRGNRSjZ1RTd3TUYyOXhGcEdCaGxJcW1p?=
 =?utf-8?B?RXRtOE1zMnJXOFB0bjBQdFVHNHg1WUxpblJmOCtnV1NxMmhTWHhsZFJrS3BC?=
 =?utf-8?B?Y0pHa2o5YmxqQnJMZndlYlcxditpOWVJTUs4WmdCVytEbERvWWtIbXJWclND?=
 =?utf-8?B?MnVaR1N6SUJ6SFpPeXpiNHRPRTFydm1XYitkR0pBaVJBbExiOWZ5RTl5bXhQ?=
 =?utf-8?B?ZU9YU2Q5S3AwaTRuK0haYldZQnhJZ0lSS05JVXhsdEVXUzFmdzBwdmZObWJP?=
 =?utf-8?B?MTl3RG92bVRzM2NWa3lVV3d6dkk1QjliNUUzRWxIbWF1c2wyMi8zZWdyTmhr?=
 =?utf-8?B?NERacGtHb0EzUHJacElMSWZOZ0JlOWtvUWJlS0hGZ3dQeGhoaW5lRWxPYmVj?=
 =?utf-8?B?YzAwbjlFZWcxNFpMenNmZitpay92dlBhbCtIVTh0NnpkWUplZUI1VUdZU1Ex?=
 =?utf-8?B?WkxHc3ovNUZORGdMWmRrMGNWajlVZzBpUXhtS2FYOHpwenVZRk1XS3JhNGpT?=
 =?utf-8?B?WExzTzg0ZnJwblVmZTZvSTUydHhqRmtwaEE3UE9JM0lrR0xUYndzMTMwRlJv?=
 =?utf-8?B?c3Q0eG1rL05sSWZOcHFIbXluSDc5ODEyZkJtN1RCakRvSmZ2VGl0N1NSdUdL?=
 =?utf-8?B?L054N2QrS2tHakoxaVpzOHI5T2FJcmR1N29CbjlOR09wcVI3VkZkREdFdzll?=
 =?utf-8?B?VmpnSlVMczNseUdIcDB2Q3o1MzYxZGZSc0I1WHJrUXhTZURkN0l5eFhuaEpy?=
 =?utf-8?B?anNwb3ltS0t6aEYxQkJpQ1FaaXYreng5OE0xVGhoWXlIRVFVYTJtUURQNXYx?=
 =?utf-8?B?RlhCWVQrRlNqczJHcGVUd2dKL1RlVTVFT0lzYVJTYW1GTjBsdTFIcGpmemE3?=
 =?utf-8?B?bytjeXFkT0NpdkJXTWV4SHgvVzY4WTk0SXZXeFQyWGxlYUlnb0NmYXNHQzBL?=
 =?utf-8?B?R21PTjVERGZvSkNzRzlRQUgwZytFTC94emVNRWJSaEpXaWo4ODlpZEVTbS92?=
 =?utf-8?B?RGJHTDh1eXJ2ME9Ra3lKc2JGaXFGTXZxdDUvN3FXZHpKVXhlMVVHTHdrdExT?=
 =?utf-8?B?VUV6MHNXNStIZjVBaU5NYzArd0dxOFJpRVVtY3pURWdvSm82SCt2c0lTVGc3?=
 =?utf-8?B?VjZ5eHh6OXFRdDduYUMwMklEWXY1R1A0VmhGUDdMTmk1SWkxcG5xeFM4bEZJ?=
 =?utf-8?B?VldRNEdBYkZwc3NOanNsYk9sRmZ4M1RuMGJWcmxJYTErWnVhaVZmdzdiVDIx?=
 =?utf-8?B?clpwN3pkTDc1S2ozSUI5bGpScWRZT01oUzV0ZjhlTnFTQ2xJMUM5M3JQWm1y?=
 =?utf-8?B?a00ycHdWeE9hOVgxNmwvaTdNTkJiS2NtYmR3NG5kR25QTzBzdHRHbURTUjdy?=
 =?utf-8?B?N2lzV3pEaXBrVWFLcG5haGdQbWxyeXZJOXBKQ3BSU2srM0pUaEFOUzdHbUZK?=
 =?utf-8?B?TXc9PQ==?=
X-OriginatorOrg: nxp.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 4ceb6c9e-9b77-4c42-67a1-08db63526ff5
X-MS-Exchange-CrossTenant-AuthSource: AM0PR04MB6452.eurprd04.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 02 Jun 2023 10:16:32.1776
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 686ea1d3-bc2b-4c6f-a92c-d99c5c301635
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: MlGtQ7tv1GvME9U/gCTyBialKuz6JrVH2p7yuq2UNOsU9Xp/nwi3N+3Jps5pqfOKPzvFEzbhNJmKI+Qx1H+zhQ==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: DU2PR04MB8855
X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED,
        DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE,
        RCVD_IN_MSPIKE_H2,SPF_HELO_PASS,SPF_PASS,T_SCC_BODY_TEXT_LINE,
        URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
        lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

Hi Jianmin,

On Fri, Jun 02, 2023 at 03:36:18PM +0800, Jianmin Lv wrote:
> On 2023/6/2 下午3:21, Liu Peibao wrote:
> > Hi all,
> > 
> > It seems that modification for current PCI enumeration framework is
> > needed to solve the problem. If the effect of this modification is not
> > easy to evaluate, for the requirement of Loongson, it should be OK that
> > do the things in Loongson PCI controller driver like discussed
> > before[1].
> > 
> > Br,
> > Peibao
> > 
> > [1] https://lore.kernel.org/all/20221114074346.23008-1-liupeibao@loongson.cn/
> > 
> 
> Agree. For current pci core code, all functions of the device will be
> skipped if function 0 is not found, even without the patch 6fffbc7ae137
> (e.g. the func 0 is disabled in bios by setting pci header to 0xffffffff).
> So it seems that there are two ways for the issue:
> 
> 1. Adjust the pci scan core code to allow separate function to be
> enumerated, which will affect widely the pci core code.
> 2. Only Adjust loongson pci controller driver as Peibao said, and any
> function of the device should use platform device in DT if function 0 is
> disabled, which is acceptable for loongson.
> 
> Thanks,
> Jianmin

How about 3. handle of_device_is_available() in the probe function of
the "loongson, pci-gmac" driver? Would that not work?