From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751917AbeFDIbU (ORCPT ); Mon, 4 Jun 2018 04:31:20 -0400 Received: from esa2.hgst.iphmx.com ([68.232.143.124]:19647 "EHLO esa2.hgst.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750997AbeFDIbS (ORCPT ); Mon, 4 Jun 2018 04:31:18 -0400 X-IronPort-AV: E=Sophos;i="5.49,476,1520870400"; d="scan'208";a="176440043" From: Bart Van Assche To: "jejb@linux.vnet.ibm.com" , "linux-kernel@vger.kernel.org" , "linux-scsi@vger.kernel.org" , "martin.petersen@oracle.com" , "evgreen@chromium.org" , "vinholikatti@gmail.com" , Stanislav Nijnikov CC: "gwendal@chromium.org" Subject: Re: [PATCH 1/7] scsi: ufs: Add Configuration Descriptor to sysfs Thread-Topic: [PATCH 1/7] scsi: ufs: Add Configuration Descriptor to sysfs Thread-Index: AQHT93nDKDRmWYOlQ02tJz1YZLeA7aRPzdeA Date: Mon, 4 Jun 2018 08:31:16 +0000 Message-ID: References: <20180529181740.195362-1-evgreen@chromium.org> <20180529181740.195362-2-evgreen@chromium.org> In-Reply-To: <20180529181740.195362-2-evgreen@chromium.org> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: authentication-results: spf=none (sender IP is ) smtp.mailfrom=Bart.VanAssche@wdc.com; x-originating-ip: [178.117.55.239] x-ms-publictraffictype: Email x-microsoft-exchange-diagnostics: 1;MWHPR04MB0431;7:D8GtitHcIMzxedqa9T85mYnVmZfhji/+9eEduh5aVR+/C5AEcNeSKIcV1aM/kuxeShs+FnL6lfbXU6RD3bVxlc4aFfTGRwztw4JzkSa1k60IYRdLAjLp6s32nFJji+UVAX9p51ZzAU238FuAe0fjZ2ydMXk7Th1AI5xqHXB6VTFifFR2080pUelkv6uc8cvLpCVPVI0WSR4pawCm542yzrtgxJrvyO2nHJ6E0GOztTSbx6dmMQX48dDvRFOxHZ6A;20:ESs6oFGF1p7nhF9rARAB6GcgqPM8Dgs4PjZgALa81t4dFHwiCILchPzOjgd4xzbopd6BK9H9v3NRjWl0EbuQgXYJH4fvs8Fia0vwL+O2SHes4mWlGVmSeubpVFE9u4TUB2wAn2ErTT6AQ8cOFDDLdxRRuDhVFoGhDql2fzEgn8E= x-ms-exchange-antispam-srfa-diagnostics: SOS;SOR; x-ms-office365-filtering-ht: Tenant x-microsoft-antispam: UriScan:;BCL:0;PCL:0;RULEID:(7020095)(4652020)(48565401081)(5600026)(4534165)(4627221)(201703031133081)(201702281549075)(2017052603328)(7153060)(7193020);SRVR:MWHPR04MB0431; x-ms-traffictypediagnostic: MWHPR04MB0431: wdcipoutbound: EOP-TRUE x-microsoft-antispam-prvs: x-exchange-antispam-report-test: UriScan:; x-ms-exchange-senderadcheck: 1 x-exchange-antispam-report-cfa-test: BCL:0;PCL:0;RULEID:(6040522)(2401047)(8121501046)(5005006)(10201501046)(93006095)(93001095)(3002001)(3231254)(944501410)(52105095)(6055026)(149027)(150027)(6041310)(201703131423095)(201702281528075)(20161123555045)(201703061421075)(201703061406153)(20161123560045)(20161123562045)(20161123558120)(20161123564045)(6072148)(201708071742011)(7699016);SRVR:MWHPR04MB0431;BCL:0;PCL:0;RULEID:;SRVR:MWHPR04MB0431; x-forefront-prvs: 069373DFB6 x-forefront-antispam-report: SFV:NSPM;SFS:(10019020)(366004)(396003)(39380400002)(376002)(346002)(39860400002)(199004)(189003)(478600001)(53936002)(11346002)(6636002)(8936002)(2616005)(476003)(446003)(110136005)(6246003)(186003)(3660700001)(25786009)(6116002)(2900100001)(7736002)(305945005)(118296001)(3846002)(14454004)(6506007)(26005)(72206003)(5660300001)(3280700002)(316002)(66066001)(486006)(6512007)(2501003)(99286004)(6436002)(102836004)(97736004)(5250100002)(105586002)(86362001)(2201001)(6486002)(36756003)(2906002)(8676002)(76176011)(39060400002)(81166006)(81156014)(229853002)(4326008)(68736007)(106356001);DIR:OUT;SFP:1102;SCL:1;SRVR:MWHPR04MB0431;H:MWHPR04MB1198.namprd04.prod.outlook.com;FPR:;SPF:None;LANG:en;PTR:InfoNoRecords;A:1;MX:1; x-microsoft-antispam-message-info: gcBS0JscMTuN0DsEMl2/D++GbuN6+F06CXTM8FuqFhlpM1ntMqeF5vuzZgc/hXlLfMQnGL3HKdfDRflNAScL0C8B7w9F1oCGmjkM1scLH+1HHjKKvVRbOAGKSwhf2zW6e79QSbrDIgWVzYq2DFxMgAMvMlcHCkM5DwW8wSI7VDuyjSXoXsSSrRXQ3bpugt1A spamdiagnosticoutput: 1:99 spamdiagnosticmetadata: NSPM Content-Type: text/plain; charset="utf-8" Content-ID: MIME-Version: 1.0 X-MS-Office365-Filtering-Correlation-Id: 5311052c-0217-49ed-16dd-08d5c9f589fd X-OriginatorOrg: wdc.com X-MS-Exchange-CrossTenant-Network-Message-Id: 5311052c-0217-49ed-16dd-08d5c9f589fd X-MS-Exchange-CrossTenant-originalarrivaltime: 04 Jun 2018 08:31:16.0935 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: b61c8803-16f3-4c35-9b17-6f65f441df86 X-MS-Exchange-Transport-CrossTenantHeadersStamped: MWHPR04MB0431 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id w548VQxu028676 On Tue, 2018-05-29 at 11:17 -0700, Evan Green wrote: > This change adds the configuration descriptor to the UFS > sysfs interface. This is done in preparation for making the > interface writable, which will enable provisioning UFS devices > via Linux. > > The configuration descriptor is laid out as a header, then a set of > (usually 8) copies of the same descriptor for each unit. Rather than > creating 8 sets of the same attribute, this interface adds a cfg_unit > file, which can be set as an index that defines which of the 8 > configuration unit descriptors are being shown through sysfs. I don't know any other example of a sysfs attribute that controls the contents of another sysfs attribute so I don't know whether this kind of behavior is acceptable for sysfs attributes. Additionally, how can these two sysfs attributes be used together from concurrently running processes without triggering a race condition? Bart.