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;
Message-ID: <e0c7d254-ace3-625c-cc83-52ca0b45e9fc@intel.com>
Date:   Fri, 8 Jul 2022 13:32:56 +0200
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101
 Firefox/91.0 Thunderbird/91.10.0
Subject: Re: [PATCH 1/2] lib/string_helpers: Introduce strsplit_u32()
Content-Language: en-US
To:     Andy Shevchenko <andy.shevchenko@gmail.com>
CC:     Andy Shevchenko <andy@kernel.org>, Mark Brown <broonie@kernel.org>,
        "ALSA Development Mailing List" <alsa-devel@alsa-project.org>,
        Takashi Iwai <tiwai@suse.com>,
        Jaroslav Kysela <perex@perex.cz>,
        <amadeuszx.slawinski@linux.intel.com>,
        Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>,
        Hans de Goede <hdegoede@redhat.com>,
        =?UTF-8?Q?P=c3=a9ter_Ujfalusi?= <peter.ujfalusi@linux.intel.com>,
        "Ranjani Sridharan" <ranjani.sridharan@linux.intel.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Liam Girdwood <lgirdwood@gmail.com>,
        "Kai Vehmanen" <kai.vehmanen@linux.intel.com>,
        Bard Liao <yung-chuan.liao@linux.intel.com>
References: <20220707091301.1282291-1-cezary.rojewski@intel.com>
 <CAHp75VceKBoxXVPP4dRYb8LQqHMMDHFp6-E2iuZ-h2RTK8PWQQ@mail.gmail.com>
From:   Cezary Rojewski <cezary.rojewski@intel.com>
In-Reply-To: <CAHp75VceKBoxXVPP4dRYb8LQqHMMDHFp6-E2iuZ-h2RTK8PWQQ@mail.gmail.com>
Content-Type: text/plain; charset="UTF-8"; format=flowed
Content-Transfer-Encoding: 7bit
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?dGZQd2diYUthcTliY0ErZ1FwR3NnNDVMU3FCV3JOVmUyWi9GMHZ3TFVNZHc3?=
 =?utf-8?B?d3dpWG81aW5EOEFSTHN1RzRrbmN2YUZGaFpueWUraXc4QVVRNDVqWkVSV3R3?=
 =?utf-8?B?Q3dDUVk1c0tsUUlqa1U3ekswYzJWVnBWYkNIODFqZFBrYUFUb1RnSVRQUzNY?=
 =?utf-8?B?VlBpWTRYK0hwZHluT2ZCUGVzYjJYenFQdXZQc0IvMld1NW5ZdW5yQ0oxcE5T?=
 =?utf-8?B?Z0YyWU5PZHVEc1liazRpWHFCWlFKTzkxRDBTMmp4RUFoSUI3WTVDb1BvNWIz?=
 =?utf-8?B?dWt4ZmI2TFB5MlZJZXZzYXd6bDRYMzhlZ1pSdCtOSExSMmo0Z054V2ZVVG10?=
 =?utf-8?B?Nyt3eDZOOUZOUmFiUDlOcnB5UklPK01sZEhZV2FnUGtFblZRaGl3ODZGVWN6?=
 =?utf-8?B?VGt5THVMNmx2Vlg0TTN4cnNsQ1N2ZW83NGZCbVg5MHBSaVhzSERweDVob2lj?=
 =?utf-8?B?eUFwYU5mY2Z0M3NMamJYcS9XZ0ZjZFFBSUhESitXU3lxZTdWZlNpN0FiYUxr?=
 =?utf-8?B?TTY2WmZVK0Z6VFdMQ1ZwUjhENko3R09HbUs3WWFSQ0xpNVlkSnhmMDkzRUls?=
 =?utf-8?B?Ukk3eTRLVXV1dmw1VFB3MW9XUXc2T2dWUnJEQXA1SUdkQlUrQXZMaDMvUVJr?=
 =?utf-8?B?V3hiWmltLzJadXkzLzNEMkZETWdWRGw1ZDlyeGM3VklaaHBlQXRtdUFvZmQr?=
 =?utf-8?B?MUJPR3VVZkNHT2o1eXd5RmtYZzZ0cXZ4WnpTQlJ0bHVJRlkybElyaGx0L1A3?=
 =?utf-8?B?SmU4SVRKYVgwejE3dkNuZit6YW5hSkdPTHMxeTZnMkY1Z0ZKRHR4aTRwc2pI?=
 =?utf-8?B?cnI5ZVEvRXZsaXB5QXAzdjM4SzRZTnRlTm03N29kQ1NQWTlZSkgwWFBKeXpZ?=
 =?utf-8?B?cmMxVUFmbjk2NFRhNitMaFNjQ0pDSmdXakJsL3d6MEx4MFdISVJodkNvWkQv?=
 =?utf-8?B?TVdrREYzTW9DRE43VXVmd0VpWWJZSHJRN05Wcm1EdHhyWVNZeEhmM243MVZ3?=
 =?utf-8?B?QURMdVZITHlZNkdrVnBacjI1Z21Sd3l4MGZwNGVjandEYnNKelB4UDZJUzU3?=
 =?utf-8?B?dmliT1Z1ZEZXOXNWa2Fzb2hzMThZeU1lbnd3QmtKNURZTTVEbzdUaTFBVmU2?=
 =?utf-8?B?bGYyT09DMDJDRTBHY0s2eUxMRDBxQVRiY0lneHlNclhwYW5zQjFXLzRIODkr?=
 =?utf-8?B?TVhaZGE2K29BUmNmd1duTXRpS3l4ekFKbGYvYUdPUzNiMGxwVjZSMzdCbzNJ?=
 =?utf-8?B?bVd0MEdsTUMxbzJGd2ZIZzFsd3ZTb3lxSEt6dE9UN1VmR05nUU4zSXI2MWMx?=
 =?utf-8?B?UTJlNlNxRFlCM3I5RzVKWC9XS3lqaXEzSE5WcVZOWjNjekRzYm1aTEQ2M3Zy?=
 =?utf-8?B?bytRSnd6MjFIdTdhdXNzanNaUGllaVN0a01ZUUx6aFNKWFFlTER5Rm5SZHdL?=
 =?utf-8?B?NHdQcFhUQ1dWYW5DWUtLb1hsc0E5aVloSTJmRmIyQUVseGZPN2VqSkY2bEN3?=
 =?utf-8?B?bG5uMlY0OTdSM04xRzZRYmp4blZuQ045bHgwSHl4WmY5SXJseVhOL2JVNXJ4?=
 =?utf-8?B?akhqNGFhK3h2U1BvTFU3endrbSs1OUgvQ20rNTlLcG5YVmtRRDJYQU5KU1pk?=
 =?utf-8?B?L2M2UHNaVUNFQVgwV3NhaTl5aGtGbzBZWWRHY21hQk9meS9XWE54ODdOM0FC?=
 =?utf-8?B?Q0p1bTV5ZGhCVlVOTVdLdFdaVm1namVpdkVET1J4cmRkNzB5bVlJcXJGU3BO?=
 =?utf-8?B?M2xZY25Fb2l1OHQ4SnJqTmYyZUpONjQzdDBaUUlXTFkrVitDbFlvQ0plZ3VI?=
 =?utf-8?B?dE0zYkVUQ2hPVDRtN3lFWVZwazJJWW5LbDF6dTRoNkFzMllNNXRJY3pmSk9E?=
 =?utf-8?B?VmRTV3h3NkJTaFZ0RS8rdFlqNmRwT2lpdWNBOTN1ak83dVlkc2pDWm1PMUJy?=
 =?utf-8?B?VlNFWmQyUUQwZ3BhNmlWd1g0ajFYQXlJSElmbXlZM0hwVkJWQW1vSktOamI5?=
 =?utf-8?B?N1laSkVmREZDV29hbmoweC9JVFFxbDlzQVZ2YUVNejNSZ1BEbEp0MUF6Vi9v?=
 =?utf-8?B?bTZnK056ekxSN0JiV0NSdno3eG5xNFBSSGQ3bW9sODlNK05sRkFLU0RBMUF1?=
 =?utf-8?B?OU1JcTYzOUhqL0RlMUIyL1ZpaUEyNHdoSmt0cGIwSnhpcGxNeW5xNUtWS1RP?=
 =?utf-8?B?eFE9PQ==?=
X-MS-Exchange-CrossTenant-Network-Message-Id: 399aa2ce-444c-4fc5-8ad7-08da60d59f0a
X-MS-Exchange-CrossTenant-AuthSource: DS0PR11MB6375.namprd11.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 08 Jul 2022 11:33:04.0165
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 46c98d88-e344-4ed4-8496-4ed7712e255d
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: NSzAr5USy4Bml44V5MUoF9mAaiDDQgU00mOPlIXpAgic8usxomdfg7mOEN+IDell2MoLI2xnm/31OWT45czYqdUeO2/3LgBtz98g90rdbMU=
X-MS-Exchange-Transport-CrossTenantHeadersStamped: BN6PR11MB3923
X-OriginatorOrg: intel.com
X-Spam-Status: No, score=-5.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,
        DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,NICE_REPLY_A,
        RCVD_IN_DNSWL_MED,SPF_HELO_NONE,SPF_NONE,T_SCC_BODY_TEXT_LINE
        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

On 2022-07-08 12:22 PM, Andy Shevchenko wrote:
> On Thu, Jul 7, 2022 at 11:03 AM Cezary Rojewski
> <cezary.rojewski@intel.com> wrote:
>>
>> Add strsplit_u32() and its __user variant to allow for splitting
>> specified string into array of u32 tokens.
> 
> And I believe we have more of this done in old code.
> Since all callers use ',' as a delimiter, have you considered using
> get_options()?


Thanks for your input, Andy.

When I'd written the very first version of this function many months 
ago, get_options() looked as it does not fulfill our needs. It seems to 
be true even today: caller needs to know the number of elements in an 
array upfront. Also, kstrtox() takes into account '0x' and modifies the 
base accordingly if that's the case. simple_strtoull() looks as not 
capable of doing the same thing.

The goal is to be able to parse input such as:

0x1000003,0,0,0x1000004,0,0

into a sequence of 6 uints, filling the *tkns and *num_tkns for the caller.

>> Originally this functionality was added for the SOF sound driver. As
>> more users are on the horizon, relocate it so it becomes a common good.
> 
> Maybe it can be fixed just there.

avs-driver, which is also part of the ASoC framework has very similar 
debug-interface. I believe there's no need to duplicate the functions - 
move them to common code instead.


Regards,
Czarek