From mboxrd@z Thu Jan 1 00:00:00 1970 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Subject: [v2,1/6] ACPI / bus: Return error code from __acpi_match_device() in one case From: Andy Shevchenko Message-Id: <1517846179.22495.27.camel@linux.intel.com> Date: Mon, 05 Feb 2018 17:56:19 +0200 To: "Rafael J. Wysocki" Cc: dmaengine , "Rafael J . Wysocki" , ACPI Devel Maling List , Sinan Kaya , Sakari Ailus , Vinod Koul List-ID: T24gU3VuLCAyMDE4LTAyLTA0IGF0IDA4OjE2ICswMTAwLCBSYWZhZWwgSi4gV3lzb2NraSB3cm90 ZToKPiBPbiBUaHUsIEZlYiAxLCAyMDE4IGF0IDk6MjAgUE0sIEFuZHkgU2hldmNoZW5rbwo+IDxh bmRyaXkuc2hldmNoZW5rb0BsaW51eC5pbnRlbC5jb20+IHdyb3RlOgo+ID4gSW5zdGVhZCBvZiBw bGF5aW5nIHRyaWNrcyB3aXRoIGxhc3QgaW52YWxpZCBlbnRyeSwKPiA+IHJldHVybiBzaW1wbGUg LUVOT0RBVEEgZXJyb3IgY29kZSBjYXN0ZWQgdG8gcG9pbnRlci4KPiA+IAo+ID4gSXQgd291bGQg YmUgZ29vZCBmb3IgZnV0dXJlIGluIGNhc2UgY2FsbGVyIHBhc3NlcyBOVUxMIHBvaW50ZXIgZm9y Cj4gPiBJRCB0YWJsZS4gTW9yZW92ZXIsIGNhbGxlciBjYW4gY2hlY2sgdGhlIGNvZGUgdG8gYmUg c3VyZSB3aGF0Cj4gPiBoYXBwZW5lZAo+ID4gaW5zaWRlIGNhbGxlZS4KCj4gPiAtICAgICAgICAg ICAgICAgICAgICAgICByZXR1cm4gaWQ7Cj4gPiArICAgICAgICAgICAgICAgICAgICAgICByZXR1 cm4gRVJSX1BUUigtRU5PREFUQSk7Cj4gCj4gU28gd2h5IGlzIHJldHVybmluZyBpZCBmcm9tIGhl cmUgYSBwcm9ibGVtPwoKSSB0aGluayB5b3UgYWxyZWFkeSBub3RpY2VkIHRoYXQgaW4gdGhlIGZv bGxvd2luZyBwYXRjaCBpdCBiZWNvbWVzIGEKcHJvYmxlbSBpZiB1c2VyIHN1cHBseSBpZHMgPT0g TlVMTC4KClRoYXQncyB3aHkgSSBhZGRlZCBhIHNlY29uZCBwYXJhZ3JhcGggdG8gdGhlIGNvbW1p dCBtZXNzYWdlIHRvIGV4cGxhaW4uCg== From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andy Shevchenko Subject: Re: [PATCH v2 1/6] ACPI / bus: Return error code from __acpi_match_device() in one case Date: Mon, 05 Feb 2018 17:56:19 +0200 Message-ID: <1517846179.22495.27.camel@linux.intel.com> References: <20180201202012.36524-1-andriy.shevchenko@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: Received: from mga07.intel.com ([134.134.136.100]:52960 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753215AbeBEP4Y (ORCPT ); Mon, 5 Feb 2018 10:56:24 -0500 In-Reply-To: Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: "Rafael J. Wysocki" Cc: dmaengine , "Rafael J . Wysocki" , ACPI Devel Maling List , Sinan Kaya , Sakari Ailus , Vinod Koul On Sun, 2018-02-04 at 08:16 +0100, Rafael J. Wysocki wrote: > On Thu, Feb 1, 2018 at 9:20 PM, Andy Shevchenko > wrote: > > Instead of playing tricks with last invalid entry, > > return simple -ENODATA error code casted to pointer. > > > > It would be good for future in case caller passes NULL pointer for > > ID table. Moreover, caller can check the code to be sure what > > happened > > inside callee. > > - return id; > > + return ERR_PTR(-ENODATA); > > So why is returning id from here a problem? I think you already noticed that in the following patch it becomes a problem if user supply ids == NULL. That's why I added a second paragraph to the commit message to explain. -- Andy Shevchenko Intel Finland Oy