From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AF014C6778C for ; Wed, 4 Jul 2018 09:43:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 719ED2086A for ; Wed, 4 Jul 2018 09:43:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 719ED2086A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=loewensteinmedical.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753672AbeGDJnL (ORCPT ); Wed, 4 Jul 2018 05:43:11 -0400 Received: from mail.steuer-voss.de ([85.183.69.95]:41652 "EHLO mail.steuer-voss.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932392AbeGDJmo (ORCPT ); Wed, 4 Jul 2018 05:42:44 -0400 X-Virus-Scanned: Debian amavisd-new at mail.steuer-voss.de Received: by mail.steuer-voss.de (Postfix, from userid 1000) id 42E7041AA2; Wed, 4 Jul 2018 11:42:40 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by mail.steuer-voss.de (Postfix) with ESMTP id 3921A41AA1; Wed, 4 Jul 2018 11:42:40 +0200 (CEST) Date: Wed, 4 Jul 2018 11:42:40 +0200 (CEST) From: Nikolaus Voss X-X-Sender: nv@fox.voss.local To: Andy Shevchenko cc: Jonathan Cameron , Hartmut Knaack , Lars-Peter Clausen , Peter Meerwald-Stadler , Lorenzo Bianconi , Linus Walleij , Xiongfeng Wang , linux-iio@vger.kernel.org, Linux Kernel Mailing List , nv@vosn.de Subject: Re: [PATCH v2 2/2] IIO: st_accel_i2c.c: Use probe_new() instead of probe() In-Reply-To: Message-ID: References: <82c6f53cfa03f9bc7c0adfc423ae65fc986a1d25.1530599660.git.nikolaus.voss@loewensteinmedical.de> User-Agent: Alpine 2.20 (DEB 67 2015-01-07) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 4 Jul 2018, Andy Shevchenko wrote: > On Wed, Jul 4, 2018 at 12:09 PM, Nikolaus Voss > wrote: >> On Wed, 4 Jul 2018, Andy Shevchenko wrote: >>> >>> On Wed, Jul 4, 2018 at 9:37 AM, Nikolaus Voss >>> wrote: >>>> >>>> On Wed, 4 Jul 2018, Andy Shevchenko wrote: >>>>> >>>>> >>>>> On Tue, Jul 3, 2018 at 9:06 AM, Nikolaus Voss >>>>> wrote: >>>>>> >>>>>> >>>>>> struct i2c_device_id argument of probe() is not used, so use >>>>>> probe_new() >>>>>> instead. >>>>>> >>>>> >>>>> This makes... >>>>> >>>>>> MODULE_DEVICE_TABLE(i2c, st_accel_id_table); >>>>> >>>>> >>>>> >>>>> ...this table obsolete IIUC. At least that's what I did when switched >>>>> to ->probe_new() in some drivers. >>>>> >>>>> If I'm mistaken (again? :-) ) I would hear from someone to point me >>>>> how it can be used after a switch. >>>> >>>> >>>> >>>> It is still used by the i2c-core in i2c_device_match() if DT and ACPI >>>> matching fails. >>> >>> >>>> And it is used to create the corresponding modaliases for >>>> driver loading. >>> >>> >>> My question is "How?!" >>> I don't really see any points to match against it after switching to >>> ->probe_new(). >>> >>> Could you point me to the code path in i2c (or OF?) core for that? >> >> >> As written above in i2c-core-base.c: i2c_device_match() -> >> i2c_match_id(driver->id_table,... >> >> This is used for driver matching before probe() or probe_new() of the device >> driver can be called. probe_new() actually is a function signature change >> only. > > Okay, IIUC we got a match. What should we do with it? The table is not > used in ->probe_new() (in i2c core), so, you can't say which line > matched there. The table is not used by the driver, but is necessary to a) bind an i2c device declared via i2c_board_info with type field set to one of the names of the i2c_device_id table to this driver b) bind an i2c device declared via DT or ACPI but with no match in of_id/ acpi_id table but an i2c_device_id table match to this driver (fallback matching) c) create the right modaliases at compile time for this driver to make module auto-loading work in case of a) and b) Niko