From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp.codeaurora.org by pdx-caf-mail.web.codeaurora.org (Dovecot) with LMTP id DEXxFQOVHltdLwAAmS7hNA ; Mon, 11 Jun 2018 15:28:23 +0000 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 557E3607BB; Mon, 11 Jun 2018 15:28:23 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on pdx-caf-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI autolearn=ham autolearn_force=no version=3.4.0 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by smtp.codeaurora.org (Postfix) with ESMTP id C6F23601C3; Mon, 11 Jun 2018 15:28:22 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org C6F23601C3 Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=holtmann.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754193AbeFKP2U convert rfc822-to-8bit (ORCPT + 20 others); Mon, 11 Jun 2018 11:28:20 -0400 Received: from coyote.holtmann.net ([212.227.132.17]:52956 "EHLO mail.holtmann.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754013AbeFKP2S (ORCPT ); Mon, 11 Jun 2018 11:28:18 -0400 Received: from marcel-macpro.fritz.box (p5B3D24B5.dip0.t-ipconnect.de [91.61.36.181]) by mail.holtmann.org (Postfix) with ESMTPSA id F38EFCF186; Mon, 11 Jun 2018 17:34:58 +0200 (CEST) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 11.4 \(3445.8.2\)) Subject: Re: [PATCH v2 15/24] net: qualcomm: MODULE_DEVICE_TABLE(serdev) From: Marcel Holtmann In-Reply-To: Date: Mon, 11 Jun 2018 17:28:16 +0200 Cc: LKML , "open list:SERIAL DRIVERS" , Lino Sanfilippo , "David S. Miller" , Stefan Wahren , Rob Herring , Johan Hovold , netdev@vger.kernel.org Content-Transfer-Encoding: 8BIT Message-Id: References: <20180611115240.32606-1-ricardo.ribalda@gmail.com> <20180611115240.32606-16-ricardo.ribalda@gmail.com> To: Ricardo Ribalda Delgado X-Mailer: Apple Mail (2.3445.8.2) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Marcel, >> the commit message is misleading me. If I build something with ACPI or DT support, then modinfo will show all modalias information for ACPI and DT compatible strings. What else does udev/modprobe actually need? Is something broken with the modalias export? > > The main purpose is to autoload drivers for devices that have been > created via sysfs or another module. > > Eg1: We have a serial port on a standard computer that has connected a > GPS module. Since it is something that is not in the ACPI nor the DT > table the user will run > > echo serdev_gps > /sys/bus/serial/devices/serial0/new_device > > Eg2 module: https://github.com/ribalda/linux/blob/415bb3f0076c2b846ebe5409589b8e1e3004f55a/drivers/tty/serdev/test_platform.c > > Modprobe does not know what module to load for that device unless > there is a matching MODULE_DEVICE_TABLE > Today, we have the same functionality for i2c devices > https://www.kernel.org/doc/Documentation/i2c/instantiating-devices but why does this have to be the driver name? I would rather say, create a generic string that describes the hardware and then use that. I think you also want the special handling, as from USB for example, that lets you reference an existing .compatible or ACPI ID as reference so that the driver_data is copied. Regards Marcel